Modernize some Python constructs (#876)

* Update __future__ import, remove __metaclass__ assignment.

* Removing obsolete encoding comment.

* Remove unneccessary object inheritance.

tests/unit/plugins/modules/test_luks_device.py

@@ -2,16 +2,13 @@
 # GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-from __future__ import absolute_import, division, print_function
-
-
-__metaclass__ = type
+from __future__ import annotations
 
 import pytest
 from ansible_collections.community.crypto.plugins.modules import luks_device
 
 
-class DummyModule(object):
+class DummyModule:
     # module to mock AnsibleModule class
     def __init__(self):
         self.params = dict()