Add python 3.11 unit test job

Python 3.11 is going to be added as required
python version testing[1] so testing it in
advance is good idea.

[1] https://governance.openstack.org/tc/reference/runtimes/2024.1.html#python-runtimes-for-2024-1

Change-Id: I77c51657d67b644ece30589f26bb795929f25bc4
diff --git a/zuul.d/project.yaml b/zuul.d/project.yaml
index 9787526..469b659 100644
--- a/zuul.d/project.yaml
+++ b/zuul.d/project.yaml
@@ -11,6 +11,7 @@
         - openstack-tox-py38
         - openstack-tox-py39
         - openstack-tox-py310
+        - openstack-tox-py311
         - tempest-full-py3:
             # Define list of irrelevant files to use everywhere else
             irrelevant-files: &tempest-irrelevant-files
@@ -128,6 +129,7 @@
         - openstack-tox-py38
         - openstack-tox-py39
         - openstack-tox-py310
+        - openstack-tox-py311
         - tempest-slow-py3:
             irrelevant-files: *tempest-irrelevant-files
         - neutron-ovs-grenade-multinode: