Merge pull request #54786 from shiywang/bump-protobuf

Automatic merge from submit-queue (batch tested with PRs 55093, 54966, 55047, 54971, 54786). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

vendor update: github.com/golang/protobuf

When I'm working on PR: https://github.com/kubernetes/kubernetes/pull/54782, I met a problem here: https://github.com/golang/protobuf/issues/372, which I think we need to update our vendor of protobuf
and I ask Dr. Stefan for suggestion, here is our coversation

shiywang [5:09 PM]
hi, Dr. Stefan i'm sorry to bother, I have a simple question, I was working on a pr which need to use protobuf custom field, and I run into this problem here: https://github.com/golang/protobuf/issues/372  which I think is due to our codebase's protobuf vendor is too old `vendor/github.com/golang/protobuf`,  do you think I can update that vendor to lastest one ?  also I noticed there's also an extend package called `vendor/github.com/gogo/protobuf/proto` what's the releationship between those two ?  which one should I update ?

sttts
[5:11 PM]
hi

[5:11]
don't know much about the proto internals either, @claytonc is probably the only one

[5:12]
create a vendor/github.com/golang/protobuf bump PR and assign it to him

shiywang [5:12 PM]
sounds good, thank you sir

so
/assign @smarterclayton
for suggestion, thanks

```release-note
NONE
```

Kubernetes-commit: 5b7ce60fcebea445b7852d8dc2bce141a2bd7a3a

vendor/github.com/golang/protobuf/proto/lib.go

@@ -73,7 +73,6 @@ for a protocol buffer variable v:
 When the .proto file specifies `syntax="proto3"`, there are some differences:
 
   - Non-repeated fields of non-message type are values instead of pointers.
-  - Getters are only generated for message and oneof fields.
   - Enum types do not get an Enum method.
 
 The simplest way to describe this is to see an example.