[llvm] [GitHub] Fix authentication for release workflow git push (PR #212634)

[Baranov Victor via llvm-commits]

https://github.com/vbvictor approved this pull request.

LGTM,
Relevant link
https://docs.github.com/en/apps/creating-github-apps/authenticating-with-a-github-app/authenticating-as-a-github-app-installation

But I think we need to wait for approval from someone who actually use this script (I dont)

https://github.com/llvm/llvm-project/pull/212634