Bug-1361570: Add index on Repository (url, active_status)

[moijes12]

Add a composite index on Repository (url, active_status) to improve query performance for PushLoader.process(). The index is create CONCURRENTLY to avoid locking table during production deployment.

Some additional notes:

• Migration uses CREATE INDEX CONCURRENTLY to avoid table locks
• Index creation is atomic=False and safe to deploy during production traffic
• Can be rolled back safely if needed via the reverse_sql in the migration

Testing Done:

• Locally tested pytest tests/etl/test_push_loader.py -v and verified that no tests fail.
• Also, checked that makemigrations works and that migrations can be applied successfully

Resolves: Bug-1361570

[moijes12]

@camd @jmaher

I have been able to add the required tests and fix them. I am facing an issue with formatting due to which I am not able to get the circleci job to create a build to work. Please can you tell me how I can fix this. All other CI jobs are working.

Update
I read through some documentation and understood how to correctly work with ruff. The code is now formatted correctly and all the ci jobs now pass.