fix: Add missing blank line for ruff formatting compliance

- Add blank line after AssertionError in connector_base.py
- Resolves ruff format check CI failure

Co-Authored-By: AJ Steers <aj@airbyte.io>

Author: devin-ai-integration[bot]

airbyte_cdk/test/standard_tests/connector_base.py

@@ -136,6 +136,7 @@ def test_check(
             and not result.errors
         ):
             raise AssertionError(f"Expected error in `check` but got success.")
+
     @classmethod
     def get_connector_root_dir(cls) -> Path:
         """Get the root directory of the connector."""