Add script to generate summary page for CI

[yuandrew]

What was changed

Added logic to show a historic summary of CI runs on main and failure rates for 7 and 30 day windows.

Future PR can be made to make things smarter to track at the specific Go test level

Why?

Help monitor test failures/flakes on main

Checklist

1. Closes

2. How was this tested:
   This only runs on main, but I temporarily allowed it to run on PRs to show behavior for testing.
   https://github.com/temporalio/sdk-go/actions/runs/25395620361?pr=2323

3. Any docs updates needed?

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Note

Medium Risk
Adds a new GitHub Actions job that calls the GitHub API to aggregate 30-day workflow/job data and write it to the run summary; failures or API/rate-limit issues could affect CI signal and timing.

Overview
Adds a new CI History Summary job to ci.yml (runs on push after all test jobs) that writes a markdown report into GITHUB_STEP_SUMMARY.

Introduces a Go tool (.github/tools/ci-history-summary) that queries GitHub Actions for the last 30 days of completed runs for the workflow/branch, aggregates per-job 7d/30d run+failure counts and pass rates, and lists recent failures (grouped/normalized and capped). Includes basic unit tests for job-collapsing and failure rendering/limits.

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[Sushisource]

I love this idea but maybe let's not do a giant bash script lol.

Also let's get in touch with @stephanos (you should loop in @THardy98 too) - I think he's done a lot of stuff like this already we can probably re-use.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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