Update CI for Dalmatian

Updates:
- run py311 func job in gate (was py310)
- add py312 testenvs to tox.ini
- did not remove py38 testenvs from tox.ini
- removed py38 classifier from setup.cfg, but did not change
  python_requires (currently it's >=3.8)

Python 3.12 unit tests will run non-voting in the gate as part of the
openstack-python3-jobs template.  Python 3.10 coverage is being handled
by tempest running in Ubuntu 22.04.

Change-Id: I72ec22780d36ea3e56386ae2bd74bf5b9806731c

.zuul.yaml

@@ -24,7 +24,7 @@
               - ^doc/.*$
               - ^releasenotes/.*$
               - ^reno.yaml$
-        - openstack-tox-functional-py310:
+        - openstack-tox-functional-py311:
             irrelevant-files: *functional-irrelevant-files
         - cinder-rally-task:
             voting: false

setup.cfg

@@ -16,7 +16,6 @@ classifiers =
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11

tox.ini

@@ -42,7 +42,7 @@ passenv =
   *_proxy
   *_PROXY
 
-[testenv:py{3,38,39,310,311}]
+[testenv:py{3,38,39,310,311,312}]
 # NOTE: Do not move the constraints from the install_command into deps, as that
 #       may result in tox using unconstrained/untested dependencies.
 #       We use "usedevelop = True" for tox jobs (except bindep), so tox does 2
@@ -62,7 +62,7 @@ install_command = {[testenv:py3]install_command}
 setenv =
   OS_TEST_PATH = ./cinder/tests/functional
 
-[testenv:functional-py{3,38,39,310,311}]
+[testenv:functional-py{3,38,39,310,311,312}]
 install_command = {[testenv:functional]install_command}
 setenv =
   {[testenv:functional]setenv}