Uses deprecated datetime.datetime.utcnow()

[thesamesam]

datetime.datetime.utcnow is deprecated since 3.12: https://docs.python.org/3/library/datetime.html#datetime.datetime.utcnow

I started with a naive patch but ran into some issue with the Bugzilla handling:

diff --git a/nattka/__main__.py b/nattka/__main__.py
index a141cea..748364d 100644
--- a/nattka/__main__.py
+++ b/nattka/__main__.py
@@ -395,7 +395,7 @@ class NattkaCommands(object):
         repo, git_repo = self.get_git_repository()
 
         with git_repo:
-            start_time = datetime.datetime.utcnow()
+            start_time = datetime.datetime.now(datetime.timezone.utc)
             packages = self.args.package
             if self.args.arch is None:
                 initial_arches = '*'
@@ -483,7 +483,7 @@ class NattkaCommands(object):
 
                 it += 1
 
-        end_time = datetime.datetime.utcnow()
+        end_time = datetime.datetime.now(datetime.timezone.utc)
         log.info(f'Time elapsed: {end_time - start_time}')
         log.info(f'Target CC: {" ".join(cc_arches)}')
 
@@ -559,7 +559,7 @@ class NattkaCommands(object):
         cache = self.get_cache()
         cache.setdefault('bugs', {})
 
-        start_time = datetime.datetime.utcnow()
+        start_time = datetime.datetime.now(datetime.timezone.utc)
         log.info(f'NATTkA starting at {start_time}')
         end_time = None
         if self.args.time_limit is not None:
@@ -579,7 +579,7 @@ class NattkaCommands(object):
                     log.info(f'Reached limit of {self.args.bug_limit} bugs')
                     break
                 if (end_time is not None
-                        and datetime.datetime.utcnow() > end_time):
+                        and datetime.datetime.now(datetime.timezone.utc) > end_time):
                     log.info('Reached time limit')
                     break
 
@@ -728,7 +728,7 @@ class NattkaCommands(object):
                               is not b.sanity_check):
                             log.info('Sanity-check flag changed, '
                                      'will recheck.')
-                        elif (datetime.datetime.utcnow()
+                        elif (datetime.datetime.now(datetime.timezone.utc)
                               - datetime.datetime.strptime(
                                 last_check, '%Y-%m-%dT%H:%M:%S')
                               > datetime.timedelta(
@@ -754,7 +754,7 @@ class NattkaCommands(object):
 
                         cache_entry = cache['bugs'][str(bno)] = {
                             'last-check':
-                                datetime.datetime.utcnow().isoformat(
+                                datetime.datetime.now(datetime.timezone.utc).isoformat(
                                     timespec='seconds'),
                             'package-list': plist_json,
                             'check-res': check_res,
@@ -889,7 +889,7 @@ class NattkaCommands(object):
                     log.info(f'New comment: {comment}')
         finally:
             self.write_cache(cache)
-            end_time = datetime.datetime.utcnow()
+            end_time = datetime.datetime.now(datetime.timezone.utc)
             log.info(f'NATTkA exiting at {end_time}')
             log.info(f'Total time elapsed: {end_time - start_time}')
 
diff --git a/nattka/bugzilla.py b/nattka/bugzilla.py
index 848f4cb..11fa6ae 100644
--- a/nattka/bugzilla.py
+++ b/nattka/bugzilla.py
@@ -92,7 +92,7 @@ class BugInfo(typing.NamedTuple):
     keywords: typing.List[str] = []
     whiteboard: str = ''
     assigned_to: str = ''
-    last_change_time: datetime.datetime = datetime.datetime.utcnow()
+    last_change_time: datetime.datetime = datetime.datetime.now(datetime.timezone.utc)
     runtime_testing_required: typing.Optional[BugRuntimeTestingState] = None
 
 
diff --git a/nattka/keyword.py b/nattka/keyword.py
index faeefa4..f109416 100644
--- a/nattka/keyword.py
+++ b/nattka/keyword.py
@@ -36,7 +36,7 @@ def keyword_sort_key(kw: str
 
 
 def update_copyright(copyright_line: str,
-                     target_year: int = datetime.datetime.utcnow().year,
+                     target_year: int = datetime.datetime.now(datetime.timezone.utc).year,
                      ) -> str:
     """
     Update copyright date and owner in `copyright_line`.
diff --git a/test/test_integration.py b/test/test_integration.py
index cc00fbd..efc8977 100644
--- a/test/test_integration.py
+++ b/test/test_integration.py
@@ -873,7 +873,7 @@ class IntegrationSuccessTests(IntegrationTestCase):
     @patch('nattka.__main__.NattkaBugzilla')
     def test_sanity_cache_expired(self, bugz, add_keywords):
         bugz_inst = self.bug_preset(bugz, initial_status=True)
-        last_check = datetime.datetime.utcnow() - datetime.timedelta(days=1)
+        last_check = datetime.datetime.now(datetime.timezone.utc) - datetime.timedelta(days=1)
         with patch('nattka.__main__.datetime.datetime') as mocked_dt:
             mocked_dt.utcnow.return_value = last_check
             self.assertEqual(