chore: Raise meaningful errors when importing a2a modules for python 3.9

PiperOrigin-RevId: 773128206

src/google/adk/a2a/converters/part_converter.py

@@ -20,9 +20,20 @@ from __future__ import annotations
 
 import json
 import logging
+import sys
 from typing import Optional
 
-from a2a import types as a2a_types
+try:
+  from a2a import types as a2a_types
+except ImportError as e:
+  if sys.version_info < (3, 10):
+    raise ImportError(
+        'A2A Tool requires Python 3.10 or above. Please upgrade your Python'
+        ' version.'
+    ) from e
+  else:
+    raise e
+
 from google.genai import types as genai_types
 
 from ...utils.feature_decorator import working_in_progress