[stable-only][2023.1] Remove CI job "tox-py311"

This job is failing in the CI since [1].

This job was added to the CI jobs as a preview job for Python 3.11, not
supported in stable/2023.1 [2]. This job was useful while this branch
was a development branch, but now it doesn't provide any useful
information.

[1]https://review.opendev.org/c/opendev/base-jobs/+/926360
[2]https://github.com/openstack/neutron/blob/stable/2023.1/setup.cfg#L17-L19

Closes-Bug: #2077885
Change-Id: I52b7820f0ef683c9cb935a7379bc145f55ffd02a

Author: ralonsoh

zuul.d/job-templates.yaml

@@ -30,12 +30,6 @@
         - openstack-tox-py310: # from openstack-python3-jobs template
             timeout: 3600
             irrelevant-files:  *irrelevant-files
-        # NOTE(ralonsoh): to be updated when "openstack-tox-py311" is defined
-        # and added to "openstack-python3-jobs" template.
-        - tox-py311:
-            voting: false
-            timeout: 3600
-            irrelevant-files:  *irrelevant-files
         - openstack-tox-cover:  # from openstack-cover-jobs template
             timeout: 4800
             irrelevant-files:  *irrelevant-files
@@ -89,10 +83,6 @@
     name: neutron-periodic-jobs
     periodic:
       jobs:
-        # NOTE(ralonsoh): to be removed when "openstack-tox-py311" is defined
-        # and added to "openstack-python3-jobs" template.
-        - tox-py311:
-            timeout: 3600
         - neutron-functional
         - neutron-functional-with-uwsgi-fips
         - neutron-fullstack