[Python] Update generated code warning version (grpc#37229)

Push back the date of changing warning to error in case so that it won't be a blocker for CSM launch.
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Closes grpc#37229

PiperOrigin-RevId: 652924647

examples/python/helloworld/helloworld_pb2_grpc.py

@@ -5,10 +5,10 @@
 
 import helloworld_pb2 as helloworld__pb2
 
-GRPC_GENERATED_VERSION = '1.64.0.dev0'
+GRPC_GENERATED_VERSION = '1.66.0.dev0'
 GRPC_VERSION = grpc.__version__
-EXPECTED_ERROR_RELEASE = '1.65.0'
-SCHEDULED_RELEASE_DATE = 'June 25, 2024'
+EXPECTED_ERROR_RELEASE = '1.66.0'
+SCHEDULED_RELEASE_DATE = 'August 6, 2024'
 _version_not_supported = False
 
 try:

src/compiler/python_generator.cc

@@ -744,8 +744,8 @@ bool PrivateGenerator::PrintPreamble(grpc_generator::Printer* out) {
       var["ToolsVersion"] = config.grpc_tools_version;
       out->Print(var, "\nGRPC_GENERATED_VERSION = '$ToolsVersion$'\n");
       out->Print("GRPC_VERSION = grpc.__version__\n");
-      out->Print("EXPECTED_ERROR_RELEASE = '1.65.0'\n");
-      out->Print("SCHEDULED_RELEASE_DATE = 'June 25, 2024'\n");
+      out->Print("EXPECTED_ERROR_RELEASE = '1.66.0'\n");
+      out->Print("SCHEDULED_RELEASE_DATE = 'August 6, 2024'\n");
       out->Print("_version_not_supported = False\n\n");
       out->Print("try:\n");
       {