Reenable 'test' label for test related pull requests (#31472)

* Reenable 'test' label

See #29660 comments

* packaging is not a valid GitHub label anymore

.github/BOTMETA.yml

@@ -1147,7 +1147,8 @@ files:
     labels: docs_pull_request
     notify: dharmabumstead
   packaging/:
-    # 'packaging' automatically added to labels
+  test/:
+    # 'test' is a component path, then 'test' label will be automatically added
 macros:
   module_utils: lib/ansible/module_utils
   modules: lib/ansible/modules