remove an unusued import

Author: gaborfeher

src/a2a/contrib/tasks/vertex_task_store.py

@@ -4,7 +4,6 @@
 try:
     import vertexai
     from vertexai import types as vertexai_types
-    from google.genai import types as genai_types
     from google.genai import errors as genai_errors
 except ImportError as e:
     raise ImportError(