Use stamina to retry on HTTP 5xx errors

[hugovk]

The last two nightly http://github.com/hugovk/dashboard runs failed due to 502 and 504 errors from GitHub:

Traceback (most recent call last):
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 237, in <module>
    main()
    ~~~~^^
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 213, in main
    candidates = check_issues(args.start, args.number, args.author, args.sort)
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 165, in check_issues
    candidates.extend(check_issue(api, issue))
                      ~~~~~~~~~~~^^^^^^^^^^^^
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 71, in check_issue
    pr = api.pulls.get(pr_number)
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/ghapi/core.py", line 63, in __call__
    return self.client(self.path, self.verb, headers=headers, route=route_p, query=query_p, data=data_p)
           ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/ghapi/core.py", line 124, in __call__
    res,self.recv_hdrs = urlsend(path, verb, headers=headers or None, decode=False, debug=debug, return_headers=True,
                         ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                 route=route or None, query=query or None, data=data or None, return_json=False, timeout=timeout)
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/fastcore/net.py", line 230, in urlsend
    return urlread(req, decode=decode, return_json=return_json, return_headers=return_headers, timeout=timeout)
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/fastcore/net.py", line 129, in urlread
    with urlopen(url, data=data, headers=headers, timeout=timeout, **kwargs) as u: res,hdrs = u.read(),u.headers
         ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/fastcore/net.py", line 120, in urlopen
    try: return urlopener().open(urlwrap(url, data=data, headers=headers), timeout=timeout)
                ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 493, in open
    response = meth(req, response)
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 602, in http_response
    response = self.parent.error(
        'http', request, response, code, msg, hdrs)
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 531, in error
    return self._call_chain(*args)
           ~~~~~~~~~~~~~~~~^^^^^^^
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 464, in _call_chain
    result = func(*args)
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 611, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 502: Bad Gateway
====Error Body====
{
  "message": "Server Error"
}

https://github.com/hugovk/dashboard/actions/runs/22535823907/job/65282954371

Traceback (most recent call last):
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 237, in <module>
    main()
    ~~~~^^
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 213, in main
    candidates = check_issues(args.start, args.number, args.author, args.sort)
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 165, in check_issues
    candidates.extend(check_issue(api, issue))
                      ~~~~~~~~~~~^^^^^^^^^^^^
  File "/home/runner/work/dashboard/dashboard/github-tools/potential_closeable_issues.py", line 71, in check_issue
    pr = api.pulls.get(pr_number)
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/ghapi/core.py", line 63, in __call__
    return self.client(self.path, self.verb, headers=headers, route=route_p, query=query_p, data=data_p)
           ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/ghapi/core.py", line 124, in __call__
    res,self.recv_hdrs = urlsend(path, verb, headers=headers or None, decode=False, debug=debug, return_headers=True,
                         ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                 route=route or None, query=query or None, data=data or None, return_json=False, timeout=timeout)
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/fastcore/net.py", line 230, in urlsend
    return urlread(req, decode=decode, return_json=return_json, return_headers=return_headers, timeout=timeout)
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/fastcore/net.py", line 129, in urlread
    with urlopen(url, data=data, headers=headers, timeout=timeout, **kwargs) as u: res,hdrs = u.read(),u.headers
         ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/_temp/setup-uv-cache/environments-v2/potential-closeable-issues-326637f8f40ca124/lib/python3.14/site-packages/fastcore/net.py", line 120, in urlopen
    try: return urlopener().open(urlwrap(url, data=data, headers=headers), timeout=timeout)
                ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 493, in open
    response = meth(req, response)
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 602, in http_response
    response = self.parent.error(
        'http', request, response, code, msg, hdrs)
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 531, in error
    return self._call_chain(*args)
           ~~~~~~~~~~~~~~~~^^^^^^^
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 464, in _call_chain
    result = func(*args)
  File "/opt/hostedtoolcache/Python/3.14.3/x64/lib/python3.14/urllib/request.py", line 611, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 504: Gateway Timeout
====Error Body====

https://github.com/hugovk/dashboard/actions/runs/22561110710/job/65347677700

[codecov]

Codecov Report

❌ Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 12.19%. Comparing base (d23ed91) to head (9861446).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
potential_closeable_issues.py	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #34      +/-   ##
==========================================
- Coverage   12.26%   12.19%   -0.07%     
==========================================
  Files          17       17              
  Lines         734      738       +4     
==========================================
  Hits           90       90              
- Misses        644      648       +4     

Flag	Coverage Δ
ubuntu-latest	12.19% <0.00%> (-0.07%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.