Update release PR message if Build zip file action is retriggered

[cesarcosta99]

One potential improvement for the Build zip file & Run smoke tests action is to ensure that, when it's run against a release branch and the release PR is open, the PR gets updated accordingly. This could be achieved either by editing the original message or posting a new one if the action is retriggered due to additional changes. Like it's done in the Prepare live branch for Jetpack Beta Builder action – #8304 (comment).

[zmaglica]

I think @Automattic/transact-architecture would own this issue, and put it to their backlog.

Assigning as part of Gamma Triage process PcreKM-yM-p2.