Tag Version (this repo) fails due to branch protection rules (OSOE-912)

[BenedekFarkas]

The last step named Commit and Push Merge Target Changes fails, because the dev branch is protected.

remote: error: GH006: Protected branch update failed for refs/heads/dev.        
remote: 
remote: - Changes must be made through the merge queue        
remote: 
remote: - Required status check "validate-gha-refs" is expected.        
To https://github.com/Lombiq/GitHub-Actions
 ! [remote rejected] dev -> dev (protected branch hook declined)
error: failed to push some refs to 'https://github.com/Lombiq/GitHub-Actions'
Error: Invalid status code: 1

1. Make the last two steps in the tag-version workflow skippable by configuration.
2. Add instructions to the readme on how to resolve it:
   • As an elevated user (with push access to dev):
     • Start a merge from the release branch to dev, but don't create a commit.
     • Revert all the file changes.
     • Merge the empty commit.
   • Otherwise:
     • Create a commit on the release branch that reverts all the file the changes (compared to dev).
     • Create a PR for the release branch and merge it.

Jira issue

[Piedone]

We can change the branch protection rule or something to allow just these. I think I have a solution, will follow up.