Add py311 in tox file

Add py311 in tox file

Change-Id: I0c129c8d3cb21a7c3546deb72737269d559c6bcc

charms/cinder-ceph-k8s/tests/unit/test_cinder_ceph_charm.py

@@ -19,6 +19,9 @@
 import json
 
 import ops_sunbeam.test_utils as test_utils
+from mock import (
+    patch,
+)
 from ops.testing import (
     Harness,
 )
@@ -82,6 +85,11 @@ class TestCinderCephOperatorCharm(test_utils.CharmTestCase):
         self.harness = test_utils.get_harness(
             _CinderCephOperatorCharm, container_calls=self.container_calls
         )
+        mock_get_platform = patch(
+            "charmhelpers.osplatform.get_platform", return_value="ubuntu"
+        )
+        mock_get_platform.start()
+
         # clean up events that were dynamically defined,
         # otherwise we get issues because they'll be redefined,
         # which is not allowed.
@@ -99,6 +107,7 @@ class TestCinderCephOperatorCharm(test_utils.CharmTestCase):
             except AttributeError:
                 pass
 
+        self.addCleanup(mock_get_platform.stop)
         self.addCleanup(self.harness.cleanup)
 
     def test_all_relations(self):

charms/cinder-ceph-k8s/tox.ini

@@ -75,6 +75,10 @@ deps = {[testenv:py3]deps}
 basepython = python3.10
 deps = {[testenv:py3]deps}
 
+[testenv:py311]
+basepython = python3.11
+deps = {[testenv:py3]deps}
+
 [testenv:cover]
 basepython = python3
 deps = {[testenv:py3]deps}