Address issues reported by ruff check (#11043)

* Resolve E713 and E714 (not in/is tests).

* Address UP018 (unnecessary str call).

* UP045 requires Python 3.10+.

* Address UP007 (X | Y for type annotations).

* Address UP035 (import Callable from collections.abc).

* Address UP006 (t.Dict -> dict).

* Address UP009 (UTF-8 encoding comment).

* Address UP034 (extraneous parantheses).

* Address SIM910 (dict.get() with None default).

* Address F401 (unused import).

* Address UP020 (use builtin open).

* Address B009 and B010 (getattr/setattr with constant name).

* Address SIM300 (Yoda conditions).

* UP029 isn't in use anyway.

* Address FLY002 (static join).

* Address B034 (re.sub positional args).

* Address B020 (loop variable overrides input).

* Address B017 (assert raise Exception).

* Address SIM211 (if expression with false/true).

* Address SIM113 (enumerate for loop).

* Address UP036 (sys.version_info checks).

* Remove unnecessary UP039.

* Address SIM201 (not ==).

* Address SIM212 (if expr with twisted arms).

* Add changelog fragment.

* Reformat.

tests/unit/plugins/modules/test_pritunl_user.py

@@ -4,7 +4,6 @@
 
 from __future__ import annotations
 
-import sys
 from unittest.mock import patch
 
 from ansible.module_utils.common.dict_transformations import dict_merge
@@ -42,10 +41,6 @@ class TestPritunlUser(ModuleTestCase):
         super().setUp()
         self.module = pritunl_user
 
-        # Add backward compatibility
-        if sys.version_info < (3, 2):
-            self.assertRegex = self.assertRegexpMatches
-
     def tearDown(self):
         super().tearDown()