Clear not_landed needinfos after patches land

[loganrosen]

Closes #3003.

Summary

• track the exact Phabricator revisions that caused each not_landed needinfo
• run cleanup in a dedicated scheduled rule that queries current pending BugBot needinfos and matches them to not_landed comments
• clear only needinfo flags attributable to the rule when every tracked revision is published or the bug is closed
• recover revision IDs for legacy needinfos once, retry inaccessible bugs on later runs, and cap cleanup at 50 bugs per run
• cover landing, resolution, historical comments, legacy tracking, and unrelated-flag safety cases

Testing

• uv run pytest -q tests/rules/test_not_landed.py tests/rules/test_not_landed_cleanup.py
• pre-commit run --all-files
• uv run python -m bugbot.rules.not_landed_cleanup (authenticated live dry run; 50 expected flag clears, capped at 50)

Checklist

• Type annotations added to new functions
• Docs added to functions touched in main classes
• Dry-run produced the expected results
• The to-be-announced tag added if this is worth announcing

[suhaibmujahid]

We need to check with @mozilla/release-management to make sure that they agree.

In any case, this fits to be in its own rule instead of an addition to the existing not_landed rule.

[loganrosen]

Moved the cleanup into a separate not_landed_cleanup rule and scheduled it after not_landed. The new rule queries live pending needinfos, verifies that each flag matches a BugBot not_landed comment by setter and timestamp, and clears it only when the bug is closed or all tracked revisions are published. It also handles legacy needinfos conservatively and caps cleanup at 50 bugs per run.