Changeset 59661

Build/Test Tools: Auto-close linked PRs on GitHub.

There are currently ~2,000 open pull requests on GitHub for wordpress-develop. Many of these were for testing changes that have already been merged.

To help prevent orphaned pull requests, this new workflow will search for any pull requests referencing the Fixed Trac tickets as noted in the commit message and close them out. For now, this only happens for push events.

Props peterwilsoncc, swissspidy, johnbillion, davidbaumwald.
Fixes #62817.