"struct field xxx_hidden_HasPassed has json tag but is not exported" - go vet doesn't pass code generated with Opaque API

[jhbrown-apeiron]

What version of protobuf and what language are you using?
Go language: google.golang.org/protobuf v1.36.0

What did you do?
I generated Go code from several proto2 .proto files, using the command line argument --go_opt=default_api_level=API_OPAQUE

I ran go vet.

What did you expect to see?

I expected go vet to have no errors on the generated code.

What did you see instead?

go vet failed, reporting has json tag but is not exported for every hidden field.

Anything else we should know about your project / environment?

❯ go version
go version go1.23.4 darwin/arm64