ci: fix release notes for release branches

[wjones127]

When we cherry-pick bug fixes onto release branches, we sometimes need to modify the commits to work on a new base. When we do that, we change the commit so it's not the same as the original merge commit from the PR. The GitHub release-notes API excludes these commits from the notes it generates. This PR reproduces the same change notes format, but uses the commit messages to grab the PRs, even if they have been rebased.

[github-actions]

Code Review

Summary: This PR adds a custom Python script to generate release notes from git commit history instead of relying solely on GitHub's API. The motivation is valid - cherry-picked commits to release branches may have different SHAs than the original merge commits, causing GitHub's API to miss them.

P1 Issues

1. Missing error handling for subprocess failures (ci/generate_release_notes.py:70-74): The get_commits_between_tags function uses check=True which will raise an exception on failure, but there is no try/except wrapper. If tags do not exist or git fails, the workflow will crash with an unclear error. Consider wrapping with proper error handling.

2. Missing PyYAML dependency: The script imports yaml but the CI workflows do not ensure this dependency is installed. GitHub Actions runners have it by default, but this implicit dependency should be documented or explicitly installed.

3. No rate limiting consideration: If a release has many PRs, the script makes one gh pr view API call per PR sequentially. For large releases, this could hit rate limits or be slow. Consider batching with gh pr list or using GraphQL.

Minor Observations (non-blocking)

• The script handles the happy path well and matches the expected output format.
• Good use of dataclasses for structured data.
• The category matching logic with wildcard support correctly mirrors GitHub's release.yml behavior.

[jackye1995]

thanks for the fix!