Update jobs for Bobcat development cycle

Updating the testing template to Bobcat testing runtime:
https://governance.openstack.org/tc/reference/runtimes/2023.2.html
Also python 2.7 testing is dropped.

Change-Id: Ief5e3a105e35ec65c6d5e3603c971d724949b2f1

.zuul.yaml

@@ -160,13 +160,15 @@
 
 - project:
     templates:
-      - openstack-python3-zed-jobs
+      - openstack-python3-antelope-jobs
       - openstack-python36-jobs
     check:
       jobs:
         - whitebox-devstack-multinode
         - whitebox-devstack-ceph-multinode
+        - openstack-tox-py39
     gate:
       jobs:
         - whitebox-devstack-multinode
         - whitebox-devstack-ceph-multinode
+        - openstack-tox-py39

setup.cfg

@@ -13,11 +13,11 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
-    Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
 
 [global]
 setup-hooks =

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.18.0
-envlist = pep8,py{27,36,38}
+envlist = pep8,py{36,38,39,310}
 skip_missing_interpreters = True
 # Automatic envs (pyXX) will only use the python version appropriate to that
 # env and ignore basepython inherited from [testenv] if we set