Use an explicit version check to import typing or typing_extensions

Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

Author: musicinmybrain

tests/test_main.py

@@ -1,9 +1,10 @@
 import pickle
 
-try:
+import sys
+
+if sys.version_info >= (3, 9):
     from typing import Annotated, get_type_hints
-except ImportError:
-    # Python < 3.9
+else:
     from typing_extensions import Annotated, get_type_hints
 
 from annotated_doc import Doc