feat: ci, stale branches tweaks

Author: mklos-kw

.github/workflows/remove_stale_branches.yml

@@ -21,3 +21,7 @@ jobs:
           ignore-unknown-authors: true
           default-recipient: "kobergj"
           dry-run: ${{ inputs.dry-run || 'false' }} # fallback to dry-run
+          exempt-branches-regex: "^(main$|master$|stable-|release-|docs$|docs-stable-)"
+          exempt-protected-branches: true
+          operations-per-run: 30
+