[8.19] (backport #19343) Aligns dependency bump workflow on run branch.

[mergify]

removes a separate branch input and uses workflow branch instead. This removes confusion of which workflow branch needs to be selected and what branch input needs to be inserted - ideally they both are the same.

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This is an automatic backport of pull request #19343 done by Mergify.

[mergify]

Cherry-pick of ab859c2 has failed:

On branch mergify/bp/8.19/pr-19343
Your branch is up to date with 'origin/8.19'.

You are currently cherry-picking commit ab859c28a.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   .github/workflows/version_bumps.yml

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[github-actions]

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[mashhurs]

resolved conflicts, lgtm~