Update dependencies for latest genproto version

[staktrace]

Update our dependencies to be compatible with the current latest release
of google.golang.org/genproto by running:

go get google.golang.org/genproto
go mod tidy

This has broken a couple of small things, which are fixed here:

• The generated var name for the embedded protobuf descriptors has
  changed, so when google.golang.org/grpc got updated due to the
  genproto update, reflection/service.go needed to be updated with
  the new name. This was changed in reflection: generate protobuf files from grpc-proto grpc/grpc-go#5799.
  The var name changed because its proto import changed as part of that
  PR, and the var name is based on the import name.

• The error message for when SendHeader is called multiple times on a
  stream has changed which broke a test that was testing the error type
  and string. This was changed upstream in server: return better status for context err when writing header grpc/grpc-go#5292.

Link: grpc/grpc-go#5799
Link: grpc/grpc-go#5292

[camh-]

Hey, thanks for your contribution @staktrace. I'll get this merged over the weekend. FYI, I'll squash merge since I prefer atomic commits, and for that, I'll re-write the PR title/description as that is used as the basis of the merge commit by my merge script. I want to see what they changed in proto gen stuff for why this var got renamed and if there might be other consequences.

[juliaogris]

Hi @staktrace - so nice to see your contribution, I hope things are well.
I unblocked the CI run, looks like it failed. You can run CI locally in activated hermit env with make ci.

[staktrace]

Thanks! It looks like the CI was failing because one of the error messages changed as well. I've updated the PR such that make ci now passes for me locally.

And feel free to edit the PR as needed!

[camh-]

Thanks for the update. I'll squash the two commits together as I prefer that all commits can pass CI, so the deps update needs to be combined with the code changes. I've updated the PR description to include the info from the commits as that will become the squash merge commit message.

[staktrace]

Thanks!