Handle synchronize events on github PRs.

[blkt]

Summary

Handle synchronize events on github PRs.

Change Type

• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

Manual and unit tests.

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[coveralls]

coverage: 52.819% (+0.004%) from 52.815%
when pulling 79f927d on enh/github-webhook-pull-request-synchronize
into 1a5c09e on main.