ci: use local contrib checkout to avoid git CDN SHA propagation failures (open-telemetry#4958)

* ci: use local contrib checkout to avoid git CDN SHA propagation failures

Install contrib packages from the already-checked-out local copy instead
of a second git+https:// clone for the getting-started and tracecontext
tox envs. Eliminates intermittent install failures when a SHA has not yet
propagated to all GitHub git CDN nodes.

- tox.ini: add CONTRIB_REPO_* per-package env vars in setenv with
  fallbacks to the existing git+https:// behavior. getting-started and
  tracecontext deps now reference these vars.
- test.yml.j2 / misc.yml.j2: add CONTRIB_REPO_* path vars to the
  top-level env block; add a contrib repo checkout step (actions/checkout)
  only for getting-started and tracecontext jobs.
- Regenerate test_0.yml, test_1.yml, misc_0.yml.

Backward compatible: when CONTRIB_REPO_* vars are unset (local dev),
tox falls back to the git+https:// URL behavior.

Mirrors the fix applied in the contrib repo:
open-telemetry/opentelemetry-python-contrib#4305

Assisted-by: Claude Sonnet 4.6

* docs: add changelog entry for CI contrib SHA propagation fix (open-telemetry#4958)

Assisted-by: Claude Sonnet 4.6

* Move longpaths git config before checkout steps on Windows

The contrib repo checkout was failing on Windows with "Filename too long"
because the longpaths config ran after the checkout. Move it to be the
first step so both checkouts benefit from it.

Assisted-by: Claude Sonnet 4.6

Author: MikeGoldsmith

.github/workflows/misc_0.yml

@@ -29,6 +29,11 @@ env:
        'main'
     ) || 'main' }}
   PIP_EXISTS_ACTION: w
+  CONTRIB_REPO_UTIL_HTTP: ${{ github.workspace }}/opentelemetry-python-contrib/util/opentelemetry-util-http
+  CONTRIB_REPO_INSTRUMENTATION: ${{ github.workspace }}/opentelemetry-python-contrib/opentelemetry-instrumentation
+  CONTRIB_REPO_INSTRUMENTATION_REQUESTS: ${{ github.workspace }}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-requests
+  CONTRIB_REPO_INSTRUMENTATION_WSGI: ${{ github.workspace }}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-wsgi
+  CONTRIB_REPO_INSTRUMENTATION_FLASK: ${{ github.workspace }}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-flask
 
 jobs:
 
@@ -59,6 +64,13 @@ jobs:
       - name: Checkout repo @ SHA - ${{ github.sha }}
         uses: actions/checkout@v4
 
+      - name: Checkout contrib repo @ ${{ env.CONTRIB_REPO_SHA }}
+        uses: actions/checkout@v4
+        with:
+          repository: open-telemetry/opentelemetry-python-contrib
+          ref: ${{ env.CONTRIB_REPO_SHA }}
+          path: opentelemetry-python-contrib
+
       - name: Set up Python 3.11
         uses: actions/setup-python@v5
         with:

.github/workflows/templates/misc.yml.j2

@@ -29,6 +29,11 @@ env:
        'main'
     ) || 'main' }}{% endraw %}
   PIP_EXISTS_ACTION: w
+  CONTRIB_REPO_UTIL_HTTP: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/util/opentelemetry-util-http
+  CONTRIB_REPO_INSTRUMENTATION: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/opentelemetry-instrumentation
+  CONTRIB_REPO_INSTRUMENTATION_REQUESTS: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-requests
+  CONTRIB_REPO_INSTRUMENTATION_WSGI: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-wsgi
+  CONTRIB_REPO_INSTRUMENTATION_FLASK: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-flask
 
 jobs:
   {%- for job_data in job_datas %}
@@ -54,6 +59,15 @@ jobs:
     steps:
       - name: Checkout repo @ SHA - ${% raw %}{{ github.sha }}{% endraw %}
         uses: actions/checkout@v4
+      {%- if job_data == "tracecontext" %}
+
+      - name: Checkout contrib repo @ ${% raw %}{{ env.CONTRIB_REPO_SHA }}{% endraw %}
+        uses: actions/checkout@v4
+        with:
+          repository: open-telemetry/opentelemetry-python-contrib
+          ref: ${% raw %}{{ env.CONTRIB_REPO_SHA }}{% endraw %}
+          path: opentelemetry-python-contrib
+      {%- endif %}
       {%- if job_data == "public-symbols-check" %}
         with:
           fetch-depth: 0

.github/workflows/templates/test.yml.j2

@@ -29,6 +29,11 @@ env:
        'main'
     ) || 'main' }}{% endraw %}
   PIP_EXISTS_ACTION: w
+  CONTRIB_REPO_UTIL_HTTP: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/util/opentelemetry-util-http
+  CONTRIB_REPO_INSTRUMENTATION: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/opentelemetry-instrumentation
+  CONTRIB_REPO_INSTRUMENTATION_REQUESTS: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-requests
+  CONTRIB_REPO_INSTRUMENTATION_WSGI: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-wsgi
+  CONTRIB_REPO_INSTRUMENTATION_FLASK: ${% raw %}{{ github.workspace }}{% endraw %}/opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-flask
 
 jobs:
   {%- for job_data in job_datas %}
@@ -38,8 +43,22 @@ jobs:
     runs-on: {{ job_data.os }}
     timeout-minutes: 30
     steps:
+      {%- if job_data.os == "windows-latest" %}
+      - name: Configure git to support long filenames
+        run: git config --system core.longpaths true
+
+      {%- endif %}
       - name: Checkout repo @ SHA - ${% raw %}{{ github.sha }}{% endraw %}
         uses: actions/checkout@v4
+      {%- if "getting-started" in job_data.tox_env %}
+
+      - name: Checkout contrib repo @ ${% raw %}{{ env.CONTRIB_REPO_SHA }}{% endraw %}
+        uses: actions/checkout@v4
+        with:
+          repository: open-telemetry/opentelemetry-python-contrib
+          ref: ${% raw %}{{ env.CONTRIB_REPO_SHA }}{% endraw %}
+          path: opentelemetry-python-contrib
+      {%- endif %}
 
       - name: Set up Python {{ job_data.python_version }}
         uses: actions/setup-python@v5
@@ -48,11 +67,6 @@ jobs:
 
       - name: Install tox
         run: pip install tox-uv
-      {%- if job_data.os == "windows-latest" %}
-
-      - name: Configure git to support long filenames
-        run: git config --system core.longpaths true
-      {%- endif %}
 
       - name: Run tests
         run: tox -e {{ job_data.tox_env }} -- -ra