Merge pull request #54957 from apelisse/update-kube-openapi

Automatic merge from submit-queue (batch tested with PRs 55004, 54957). 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>.

Update kube-openapi to use validation

**What this PR does / why we need it**: Moves openapi validation code to kube-openapi, so that we can move the rest of the code to apimachinery repository, so that later we can use it from both the client and the server.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #Nothing

**Special notes for your reviewer**:

**Release note**:
```release-note
NONE
```

Kubernetes-commit: 55e216f56eac0082acc6be655d9ae09cf9ba38a8

vendor/k8s.io/apimachinery/pkg/util/mergepatch/errors.go

@@ -29,6 +29,7 @@ var (
 	ErrBadPatchFormatForRetainKeys          = errors.New("invalid patch format of retainKeys")
 	ErrBadPatchFormatForSetElementOrderList = errors.New("invalid patch format of setElementOrder list")
 	ErrPatchContentNotMatchRetainKeys       = errors.New("patch content doesn't match retainKeys list")
+	ErrUnsupportedStrategicMergePatchFormat = errors.New("strategic merge patch format is not supported")
 )
 
 func ErrNoMergeKey(m map[string]interface{}, k string) error {