Import Callable from typing for Python 3.10 compat

- Python 3.10 no longer provides Callable in collections
- We now import it from typing, to be consistent with previous imports
- See https://docs.python.org/3/whatsnew/3.10.html#pep-612-parameter-specification-variables

splitgraph/ingestion/singer/common.py

@@ -1,8 +1,7 @@
 import logging
 import traceback
-from collections import Callable
 from functools import wraps
-from typing import Any, Dict, Optional
+from typing import Any, Callable, Dict, Optional
 
 from psycopg2.sql import SQL, Identifier