Lock in Manifest schema version

[strutt]

This was done by:

• adding integration/unit tests to ansible to check all examples of old manifests still load after schema changes
• current schema = locked schema version
• tests are done automatically by github CI

Summary

• Routine Change
• ❗ Breaking Change
• 🤖 Operational or Infrastructure Change
• ✨ New Feature
• ⚠️ Potential issues that might be caused by this change

Add any other relevant notes or explanations here. Remove this line if you have nothing to add.

[Sourceless]

LGTM