[bug] unable to delete PR environment if new PR has the same head ref

[gilzow]

Where on docs.platform.sh should be changed?

This is an edge case.

The deactivate_environment job in the manage-environment.yaml workflow has a bug. Steps to reproduce:

1. Open a PR from a branch (ie not a fork) with a ref of foobar (example ref)
2. PR environment fails to deploy on Platform.sh and gets stuck
3. Create a new branch from main, merge branch in step 1 into new branch
4. Push to github and open a new PR
5. Manage Environment:deactivate_environment job will trigger but fail due to the ref being the same between the two branches even though the branch names are not

What exactly should be updated?

we need to figure out how to get just the branch name involved in the PR.

Additional context

No response