Update gate jobs as per the 2025.1 cycle testing runtime

As per 2025.1 testing runtime[1], we need to test on Ubuntu
Noble and python 3.9 to 3.12.

Tracking: https://etherpad.opendev.org/p/migrate-to-noble

[1] https://governance.openstack.org/tc/reference/runtimes/2025.1.html

Change-Id: Ib7bca90e966bf71f26aa072fbe0fc2c48ded04f9

.zuul.yaml

@@ -5,14 +5,14 @@
     check:
       jobs:
         - openstack-tox-pep8
-        - openstack-tox-py38
         - openstack-tox-py39
         - openstack-tox-py310
         - openstack-tox-py311
+        - openstack-tox-py312
     gate:
       jobs:
         - openstack-tox-pep8
-        - openstack-tox-py38
         - openstack-tox-py39
         - openstack-tox-py310
         - openstack-tox-py311
+        - openstack-tox-py312

setup.cfg

@@ -6,7 +6,7 @@ description_file =
 author = OpenStack
 author_email = openstack-discuss@lists.openstack.org
 home_page = https://opendev.org/openstack/devstack-tools/src/branch/master/README.rst
-python_requires = >=3.8
+python_requires = >=3.9
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -17,10 +17,10 @@ classifier =
     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
+    Programming Language :: Python :: 3.12
 
 [files]
 packages =