Deprecate `SchemaIntermediateState` bucket

[infrmtcs]

We're not currently using the bucket for anything, and it can cause database corruption due to wrong pebble library usages, so we can avoid reading the bucket.

[CodeMongerrr]

Hi, I want to take up this issue, and I had a couple of doubts before proceeding.

When we say deprecate SchemaIntermediateState, do we mean:
1. Keep the bucket/field in the schema but stop using it going forward?
→ This would maintain backwards compatibility, but the deprecated field remains in the DB.

or
2. Completely remove it from the schema and not include it in new database versions?
→ In this case, we will need to update migrations.go to correctly handle older databases and write tests to ensure the migration path works.

Both approaches require changes in the migration logic, but the second one requires a full schema cleanup. I want to confirm which direction we want to take before I implement the solution.

Thanks!

[CodeMongerrr]

Can you let me know about this? I want to make a contribution to Juno, if there are any other issues which might need attention, do let me know know, I used to work with Juno when I was an Intern @infrmtcs