feat: handle ready_for_review webhook action

[drazisil-codecov]

Summary

• Adds GitHubPullRequestActions constants class to webhook_handlers/constants.py
• Adds ready_for_review to the list of actions that trigger PullsSync
• Refactors pull_request() handler to use the new constants instead of bare strings

Test plan

• New test: test_pull_request_ready_for_review_triggers_pulls_sync — verifies pulls_sync is called when action is ready_for_review
• Existing tests pass: test_pull_request_triggers_pulls_sync_task_for_valid_actions, test_pull_request_updates_title_if_edited, test_pull_request_exits_early_if_repo_not_active

Closes https://github.com/codecov/core-engineering/issues/64

🤖 Generated with Claude Code

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Note

Low Risk
Low risk: small change to GitHub webhook routing that only expands the set of PR actions that enqueue pulls_sync, with a focused unit test added.

Overview
The GitHub pull_request webhook now triggers TaskService().pulls_sync when the action is ready_for_review, aligning behavior with other PR lifecycle actions.

PR action handling is refactored to use a new GitHubPullRequestActions constants class (including a shared PULLS_SYNC_ACTIONS list), and a test is added to assert the new ready_for_review behavior.

^{Reviewed by Cursor Bugbot for commit 8ae9a82. Bugbot is set up for automated code reviews on this repo. Configure here.}

[sentry]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.90%. Comparing base (d507da5) to head (8ae9a82).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #920   +/-   ##
=======================================
  Coverage   91.90%   91.90%           
=======================================
  Files        1316     1316           
  Lines       50643    50654   +11     
  Branches     1625     1625           
=======================================
+ Hits        46541    46552   +11     
  Misses       3796     3796           
  Partials      306      306           

Flag	Coverage Δ
apiunit	94.95% <100.00%> (+<0.01%)	⬆️

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[codecov-notifications]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

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[thomasrockhu-codecov]

nit: alphabetize this list, and separate EDITED after (could even add whitespace before). I got confused and thought EDITED was part of PULLS_SYNC_ACTIONS