Add resiliant repair for raw manifest data on sync

[mdellweg]

In case the data field was not properly populated during sync, we download it again and save it to the database.

📜 Checklist

• Commits are cleanly separated with meaningful messages (simple features and bug fixes should be squashed to one commit)
• A changelog entry or entries has been added for any significant changes
• Follows the Pulp policy on AI Usage
• (For new features) - User documentation and test coverage has been added

See: Pull Request Walkthrough

[mdellweg]

Since the other patch (revert) landed in 2.26, should we backport this to 2.27 and 2.28?
Would that be enough runway to make the final migration in 2.29?

[dralley]

If this is going in main then I think it would make sense to backport, yes

[gerrod3]

We also need this change here:

pulp_container/pulp_container/app/tasks/sync_stages.py

Lines 530 to 533 in 9d40f0c

	if manifest := await Manifest.objects.filter(
	digest=digest, pulp_domain=get_domain()
	).afirst():
	content_data = json.loads(manifest.data)