Remove pytest.db_test marker from SQLite tests

[choo121600]

Part of #52020

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[potiuk]

Hmm.. Some testa are still failing :(

[choo121600]

I removed the pytestmark = pytest.mark.db_test marker.

However, since some tests still require a database connection, I kept @pytest.mark.db_test for those specific test functions.

Another change is the use of mock_connection with MagicMock. This was added to address the SQLAlchemy ORM initialization error that previously caused CI failures.

[potiuk]

I removed the pytestmark = pytest.mark.db_test marker.

However, since some tests still require a database connection, I kept @pytest.mark.db_test for those specific test functions.

Another change is the use of mock_connection with MagicMock. This was added to address the SQLAlchemy ORM initialization error that previously caused CI failures.

Nice ! Thank you !