ios test changes (#35510)

* Fix over-byte

* Update ios tests to call `provider`

To continue to support testing `connection: local`

* Fix command dict handling in ios_user

* Clean up unit tests, too

lib/ansible/modules/network/ios/ios_user.py

@@ -181,12 +181,12 @@ def validate_privilege(value, module):
 
 
 def user_del_cmd(username):
-    return json.dumps({
+    return {
         'command': 'no username %s' % username,
         'prompt': 'This operation will remove all username related configurations with same name',
         'answer': 'y',
         'newline': False,
-    })
+    }
 
 
 def map_obj_to_commands(updates, module):