Migration to Repository Rulesets (Fix Template Push)

Description The "Push to Template Repo" action is failing because the standard GITHUB_TOKEN cannot bypass branch protection rules. We need to move from "Legacy Branch Protection" to "Repository Rulesets" to allow automation to work securely.

To-Do List [ ] Enable Rulesets: Transition from "Branch Protection Rules" to "Repository Rulesets" for the main branch.

[ ] Configure Bypass Actors: Add the GitHub Actions actor to the "Bypass List" within the ruleset.

[ ] Verify Permissions: Ensure the workflow YAML explicitly includes permissions: contents: write.

[ ] Standardize: Once verified, evaluate rolling this ruleset out across the entire H5BP organization to ensure "plumbing" consistency.