Remove internal/api_implementation.Version()

api_implementation.Version() is not useful which returns a constant 2.

PiperOrigin-RevId: 755591977

Author: anandolee

python/google/protobuf/internal/api_implementation.py

@@ -131,12 +131,6 @@ def Type():
   return _implementation_type
 
 
-# See comment on 'Type' above.
-# TODO: Remove the API, it returns a constant. b/228102101
-def Version():
-  return 2
-
-
 # For internal use only
 def IsPythonDefaultSerializationDeterministic():
   return _python_deterministic_proto_serialization