fix: remove unused datetime import

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

Author: devin-ai-integration[bot]

airbyte_cdk/sources/file_based/file_based_stream_reader.py

@@ -5,7 +5,7 @@
 import logging
 import time
 from abc import ABC, abstractmethod
-from datetime import datetime, timezone
+from datetime import timezone
 from enum import Enum
 from io import IOBase
 from os import makedirs, path