style(db): fix Black formatting for connection and schema modules

Remove extraneous trailing newlines from db/connection.py and
db/schema.py to satisfy Black formatting requirements.

Author: Sakeeb91

db/connection.py

@@ -244,4 +244,3 @@ async def close_database() -> None:
     if _db_manager:
         await _db_manager.close()
         _db_manager = None
-

db/schema.py

@@ -372,4 +372,3 @@ async def get_sample_data(
             error=str(e),
         )
         return []
-