Update functional jobs for 2023.2

Based on the python runtimes for 2023.2 [0], we should be running
functional jobs on python 3.9 and python 3.10.

This patch updates the functional jobs in .zuul.yaml and updates
tox.ini with a generative section to define all the relevant
functional testenvs.

[0] https://governance.openstack.org/tc/reference/runtimes/2023.2.html

Change-Id: Ia098cadbc1fcd8a5d0fbebf0022c5899eabbf863

.zuul.yaml

@@ -44,15 +44,6 @@
       # Hardcode brick-cinderclient path so the job can be run on other repo patches
       zuul_work_dir: src/opendev.org/openstack/python-brick-cinderclient-ext
 
-- job:
-    name: brick-cinderclient-dsvm-functional-py38
-    parent: brick-cinderclient-dsvm-functional-base
-    # need to specify a platform that has python 3.8 available
-    nodeset: openstack-single-node-focal
-    vars:
-      python_version: 3.8
-      tox_envlist: functional-py38
-
 - job:
     name: brick-cinderclient-dsvm-functional-py39
     parent: brick-cinderclient-dsvm-functional-base
@@ -61,6 +52,15 @@
       python_version: 3.9
       tox_envlist: functional-py39
 
+- job:
+    name: brick-cinderclient-dsvm-functional-py310
+    parent: brick-cinderclient-dsvm-functional-base
+    # python 3.10 is the default in ubuntu 22.04 (jammy)
+    nodeset: openstack-single-node-jammy
+    vars:
+      python_version: 3.10
+      tox_envlist: functional-py310
+
 - project:
     templates:
       - check-requirements
@@ -69,9 +69,9 @@
       - release-notes-jobs-python3
     check:
       jobs:
-        - brick-cinderclient-dsvm-functional-py38
         - brick-cinderclient-dsvm-functional-py39
+        - brick-cinderclient-dsvm-functional-py310
     gate:
       jobs:
-        - brick-cinderclient-dsvm-functional-py38
         - brick-cinderclient-dsvm-functional-py39
+        - brick-cinderclient-dsvm-functional-py310

tox.ini

@@ -45,11 +45,7 @@ setenv =
   OS_TEST_PATH=./brick_cinderclient_ext/tests/functional
 passenv = OS_*
 
-[testenv:functional-py38]
-setenv =
-  {[testenv:functional]setenv}
-
-[testenv:functional-py39]
+[testenv:functional-py{3,38,39,310,311}]
 setenv =
   {[testenv:functional]setenv}