clean: remove unused method

custom_pgvector.py

@@ -567,16 +567,3 @@ class CustomPGVector(VectorStore):
             column_name=column_name,
             **kwargs,
         )
-
-    @classmethod
-    def connection_string_from_db_params(
-        cls,
-        driver: str,
-        host: str,
-        port: int,
-        database: str,
-        user: str,
-        password: str,
-    ) -> str:
-        """Return connection string from database parameters."""
-        return f"postgresql+{driver}://{user}:{password}@{host}:{port}/{database}"