Automate cherry-pick pull requests for release branches #9485

Cherry-picking commits from develop into release branches is currently a manual process in rocm-systems and rocm-libraries. Preparing the branch and pull request takes maintainer time and leaves room for mistakes.

Add the same manually triggered GitHub Actions workflow to rocm-systems and rocm-libraries. A maintainer provides one or more commits from develop, a target release/therock-X.Y or release/bkc/therock-X.Y-YYYYMMDD branch, and a JIRA ID when required. The workflow validates the request, cherry-picks the commits in the supplied order onto a new branch, and opens a pull request against the release branch using the repository’s existing GitHub App. If validation fails or a cherry-pick conflicts, it reports the problem without pushing a branch or opening a pull request.