[Python example] Fix version in generated code in example folder (grp…

…c#37665)

Fix: grpc#37610
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examples/python/helloworld/helloworld_pb2_grpc.py

@@ -5,7 +5,7 @@
 
 import helloworld_pb2 as helloworld__pb2
 
-GRPC_GENERATED_VERSION = '1.67.0.dev0'
+GRPC_GENERATED_VERSION = '1.66.0'
 GRPC_VERSION = grpc.__version__
 _version_not_supported = False