Two workflows still run actions/github-script@v6 on retired Node 16 #23

GitHub retired the Node 16 runner that actions/github-script@v6 uses.

• git-tag-github-release.yml:51
• open-pr.yml:117

check-workflow-status.yml already runs @v7, so the repo is inconsistent as well as behind.

Reproduce: actionlint -shellcheck= .github/workflows/

the runner of "actions/github-script@v6" action is too old to run on
GitHub Actions. update the action's version to fix this issue [action]

Fix: move both to @v7. The scripts in each need a read before switching, since v7 moved to Node 20.

Found while reviewing #20. Reported by actionlint, which #21 proposes adding to CI.