closes#4373.
workflow triggers based on commit message regex do not seem to be easily possible.

To verify that both workflows are basically the same now, seecbee05d

Todo when merged:

• update the how-to-release wiki page a bit more
• update the test-pypi project to use the new workflow file name
• update repo settings to forbid pushes to master also for admins (will no longer be necessary even for tags)
• revert the temporary version and workflow trigger changes
• includeBump sigstore/gh-action-sigstore-python from 2.1.1 to 3.0.0 #4409