Merge pull request #30630 from silasbw/short-n0

Automatic merge from submit-queue

Add a short `-n` for `kubectl --namespace`

fixes #24078

 `--namespace` is a very common flag for nearly every `kubectl` command we have. We should claim `-n` for it.

docs/devel/kubectl-conventions.md

@@ -142,6 +142,7 @@ list when adding new short flags
 
   * `-f`: Resource file
     * also used for `--follow` in `logs`, but should be deprecated in favor of `-F`
+  * `-n`: Namespace scope
   * `-l`: Label selector
     * also used for `--labels` in `expose`, but should be deprecated
   * `-L`: Label columns