Issue #3629274: Use raw key value for container rebuild test

Closes #3629274

The container_rebuild_test module used the state service to count container rebuilds. The state service adds caching that is unnecessary for this test.

This merge request uses a dedicated key/value collection for the container rebuild counter. It also updates RebuildScriptTest and removes the now-unnecessary state cache refreshes.

Testing

• PHP syntax checks passed.
• PHPCS passed.
• RebuildScriptTest was not run locally because a functional test environment is not configured. It will be exercised by CI.

AI-Generated: Yes. I used ChatGPT to help analyse the issue and draft the initial change. I reviewed the resulting diff and ran the checks reported above locally.