title: How to add commits to merged azure Devops pull request (refs/pull/*/merge)
body: <p>I have super repository with 4 submodules.
  I want to do a pull request only on the super repo and that the pipeline will do the merge in the other repos.
  So i want to add a merge stage in my pipeline that will merge my sub modules hashes to the main head branch in the ropes.
  That mean that i need to change the super repo submodules hashes that is being merged by the pull request
  But unfortunately i cannot add commits to local merge branch (refs/pull/*/merge) that is being pushed by the pipeline eventually.</p>
  <p>What can I do?</p>