Add isort and flake8 to CI (#869)

* Run isort.

* Clean up unused assignments.

* Add flake8 linting step.

plugins/module_utils/openssh/utils.py

@@ -6,6 +6,8 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 from __future__ import absolute_import, division, print_function
+
+
 __metaclass__ = type
 
 import os
@@ -15,6 +17,7 @@ from struct import Struct
 
 from ansible.module_utils.six import PY3
 
+
 # Protocol References
 # -------------------
 # https://datatracker.ietf.org/doc/html/rfc4251