[stable-5] Remove unneccessary imports (#5977)

* Remove unneccessary imports (#5940)

* Remove unneccessary imports.

* Keep unnecessary imports in module_utils - for now.

* Make older sanity tests shut up.

* Also make flake8 happier.

(cherry picked from commit 2b8ac3c629)

* Re-add os import.

plugins/callback/counter_enabled.py

@@ -27,7 +27,6 @@ DOCUMENTATION = '''
 from ansible import constants as C
 from ansible.plugins.callback import CallbackBase
 from ansible.utils.color import colorize, hostcolor
-from ansible.template import Templar
 from ansible.playbook.task_include import TaskInclude