We'll want to add some tests to make sure the managing bootimages hasn't broken our existing functionality and that our new feature works. Proposed flow:

• opt in an existing machineset to updates
• update a GCP machineset with a dummy "bootimage"
• wait for machineset to be reconciled
• check if the machineset is restored to original value
• if it matches -> success

1/30/24: Updated based on enhancement discussions