Exclude grpc_generator.cc from linting as its a vendored file

Signed-off-by: Dom Del Nano <ddelnano@gmail.com>

Author: ddelnano

.arclint

@@ -34,6 +34,7 @@
     "(^src/ui/src/types/schema\\.ts$)",
     "(^third_party/cpplint/cpplint.py$)",
     "(^third_party/gogoproto/gogo.proto$)",
+    "(^third_party/protoc-gen-grpc-web/grpc_generator.cc$)",
     "(c_cpp_properties.json$)",
     "(go\\.mod$)",
     "(go\\.sum$)"