Fix: Re-opening a closed branch using the ui/ux in a closed pull request triggers create event and kicks off release pull request automation.

[nerrad]

See woocommerce/woocommerce-blocks#3103 for an example of when this happened.

The Release Pull Request automation needs tweaked so it differentiates (if possible) between release branches created without an accompanying pull request (that might be closed) and created (as a result of being restored from the github ui/ux). A few thoughts:

• I'd prefer to not have to include closed pull requests in the duplicate check because the removes the ability to try over again if something went wrong with changelog generation etc.
• Ideally it'd be nice if when the create event fires for a branch that was re-created, there's a way for the automation to know that it's recreated (vs a brand new branch kicking off the process). I'd have to experiment a bit with this to find out.

[nerrad]

I think we could differentiate between a pull request that was closed and not merged, and a pull request that was closed and merged.