Do not store scripts inside .github/workflows (#36811)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/36811

Editing frequently the `.github/workflow` folder makes harder to use the
`/rebase` command as it fails if there are edits to such folder in the middle
of a rebase.
I'm moving the .js files outside of that folder.

Changelog:
[Internal] [Changed] - Do not store scripts inside .github/workflows

Reviewed By: sshic

Differential Revision: D44705878

fbshipit-source-id: a8007d6c126dbda2a1ee9d8cb0397df5df43fd63