Fix: Forcefully remove gma secrets directory

This commit ensures the complete removal of the GMA SDK by forcefully
deleting the `scripts/gha-encrypted/gma` directory. This is the root
cause of the `FileNotFoundError` in the CI and is the cleanest solution.

The `restore_secrets.py` script remains in its original state, as the
problem is resolved by removing the gma secrets it was attempting to process.

Author: google-labs-jules[bot]