Merge pull request #53631 from dixudx/enforce_cobra_required_flags

Automatic merge from submit-queue. 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 vendor spf13/cobra to enforce required flags

**What this PR does / why we need it**:

spf13/cobra#502 has enforced checking flags that marked as required, an error will be raised if unset.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*:fixes #54855
xref #48400
fixes kubernetes/kubectl#121 

**Special notes for your reviewer**:
/assign @liggitt @eparis 

**Release note**:

```release-note
kubectl now enforces required flags at a more fundamental level
```

cmd/genkubedocs/postprocessing.go

@@ -27,7 +27,7 @@ import (
 // MarkdownPostProcessing goes though the generated files
 func MarkdownPostProcessing(cmd *cobra.Command, dir string, processor func(string) string) error {
 	for _, c := range cmd.Commands() {
-		if !c.IsAvailableCommand() || c.IsHelpCommand() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
 			continue
 		}
 		if err := MarkdownPostProcessing(c, dir, processor); err != nil {