Remove unnecessary files from 'protoc_sources'

If a file is already included in 'protobuf_sources', there is no need to have
the same file in 'protoc_sources', as the 'protoc' target already depends on
'protobuf' target.

This is a mechanical cleanup for GYP build.  There must be no difference in the
build artifacts anyway.

This is a preparation for #803.

#codehealth

PiperOrigin-RevId: 563447681

src/protobuf/protobuf.gyp

@@ -75,14 +75,10 @@
     ],
     # Sources for protoc (common part and C++ generator only).
     'protoc_sources': [
-      '<!@(<(glob_protobuf) . cpp_features.pb.cc)',
-      '<!@(<(glob_protobuf) . "*.cc" --exclude "*.pb.cc" reflection_tester.cc)',
       '<!@(<(glob_protobuf) compiler "*.cc" --exclude "*_tester.cc" fake_plugin.cc main.cc)',
       '<!@(<(glob_protobuf) compiler/allowlists "*.cc")',
       '<!@(<(glob_protobuf) compiler/cpp "**/*.cc")',
-      '<!@(<(glob_protobuf) io "*.cc")',
       'custom_protoc_main.cc',
-      '<!@(<(glob) --notest --base <(protobuf_root)/third_party/utf8_range "*.cc")',
     ],
   },
   'targets': [