Fix kubectl-ns plugin help text

The plugin help text was not consistent - using `ns` in some cases and
`kubectl ns` in others:

    $ ./kubectl-ns -h
    ...
    Usage:
      ns [new-namespace] [flags]

    Examples:

            # view the current namespace in your KUBECONFIG
            kubectl ns

            ...

    Flags:
      -h, --help                           help for ns
      ...

With cobra 1.8.1 we can fix the issue by annotating the command so the
help text matches the way we use the command. With this change we can
use the executable name (kubectl-ns) as the `Use` argument, and have
`kubectl ns` in the help text.

Issues:
- Requires Cobra release including spf13/cobra#2070
- Tested using local cobra with the require fix.

staging/src/k8s.io/sample-cli-plugin/go.mod

@@ -5,7 +5,7 @@ module k8s.io/sample-cli-plugin
 go 1.21.3
 
 require (
-	github.com/spf13/cobra v1.7.0
+	github.com/spf13/cobra v1.8.0
 	github.com/spf13/pflag v1.0.5
 	k8s.io/cli-runtime v0.0.0
 	k8s.io/client-go v0.0.0
@@ -69,6 +69,7 @@ require (
 )
 
 replace (
+	github.com/spf13/cobra => /home/nsoffer/src/cobra
 	k8s.io/api => ../api
 	k8s.io/apimachinery => ../apimachinery
 	k8s.io/cli-runtime => ../cli-runtime

staging/src/k8s.io/sample-cli-plugin/pkg/cmd/ns.go

@@ -82,6 +82,9 @@ func NewCmdNamespace(streams genericiooptions.IOStreams) *cobra.Command {
 		Short:        "View or set the current namespace",
 		Example:      fmt.Sprintf(namespaceExample, "kubectl"),
 		SilenceUsage: true,
+		Annotations: map[string]string{
+			cobra.CommandDisplayNameAnnotation: "kubectl ns",
+		},
 		RunE: func(c *cobra.Command, args []string) error {
 			if err := o.Complete(c, args); err != nil {
 				return err