Moves supported python runtimes from version 3.8 to 3.10

Within 2023.2 python version 3.9 and 3.10 are the
supported python runtimes [1].
[1] https://review.opendev.org/c/openstack/governance/+/872232

Change-Id: Ibea17ce03a0e4f5ef018afeb934660e0dc1bfc60

.zuul.yaml

@@ -1,12 +1,12 @@
 - job:
     name: castellan-functional-vault
-    parent: openstack-tox-py38
+    parent: openstack-tox-py310
     description: |
       Run tox functional-vault target
     required-projects:
       - name: openstack/castellan
     vars:
-      tox_envlist: functional-vault
+      tox_envlist: functional-vault-py310
 
 - job:
     name: castellan-functional-devstack
@@ -59,7 +59,7 @@
         - barbican-tempest-plugin-simple-crypto-castellan-src
     templates:
       - check-requirements
-      - openstack-python3-antelope-jobs
+      - openstack-python3-jobs
       - periodic-stable-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3

setup.cfg

@@ -6,7 +6,7 @@ description_file =
 author = OpenStack
 author_email = openstack-discuss@lists.openstack.org
 home_page = https://docs.openstack.org/castellan/latest/
-python_requires = >=3.8
+python_requires = >=3.9
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -15,8 +15,8 @@ classifier =
     Operating System :: POSIX :: Linux
     Programming Language :: Python
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: Implementation :: CPython