Run the bootstrap schedule test in CI #132

The bootstrap schedule regression test added in #131 (.github/scripts/tests/bootstrap-schedules.test.py) does not run in CI. verify-package-updates.yml runs only update-packages.test.py and bootstrap-package-update-safety.test.py, and its path filters leave out the new test and .github/scripts/bootstrap-common-workflows.sh. A later edit to the Update Packages template could break the weekly schedule without any check failing.

Acceptance:

• CI runs bootstrap-schedules.test.py when the test or bootstrap-common-workflows.sh changes (in verify-package-updates.yml or a small dedicated workflow), in a PR separate from any bootstrap template change so the rollout safety guard stays meaningful.
• The README's offline regression checks list it.
• update-packages.yml's runs-on input description says "scheduled update" instead of "daily update".