Fix issues related to py312 compatibility

Summary of changes:
- Bump flake8 from 3.9.2 to 7.1.1
- Add py312 section to tox.ini [testenv]
- Minor change to unit test
- Update zuul.yaml to use openstack-python3-charm-jobs

Change-Id: I3f2d8bce2c38259eebc6182d24a4812210152c4f

.zuul.yaml

@@ -1,4 +1,4 @@
 - project:
     templates:
-      - openstack-python3-charm-yoga-jobs
+      - openstack-python3-charm-jobs
       - openstack-cover-jobs

tox.ini

@@ -70,6 +70,11 @@ basepython = python3.8
 deps = -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
 
+[testenv:py312]
+basepython = python3.12
+deps = -r{toxinidir}/test-requirements.txt
+commands = stestr run --slowest {posargs}
+
 [testenv:py310]
 basepython = python3.10
 deps = -r{toxinidir}/test-requirements.txt
@@ -77,7 +82,7 @@ commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
 basepython = python3
-deps = flake8==3.9.2
+deps = flake8==7.1.1
        git+https://github.com/juju/charm-tools.git
 commands = flake8 {posargs} src unit_tests
 

unit_tests/test_prometheus_mysql_exporter_handlers.py

@@ -260,9 +260,10 @@ class TestPrometheusMySQLExporterHandlers(test_utils.PatchHelper):
     def test_stop_prometheus_exporter_service(self):
         handlers.stop_prometheus_exporter_service()
         self.service_stop.assert_called_once_with(self._svc_name)
-        self.remove_state.has_calls(
+        expected_calls = [
             mock.call("snap.prometheus-exporter.configed"),
-            mock.call("snap.prometheus-exporter.started"),
-        )
+            mock.call("snap.prometheus-exporter.started")
+        ]
+        self.remove_state.assert_has_calls(expected_calls)
         self.status_set.assert_called_once_with(
             "active", "Stop prometheus exporter service")