CI: fix (and update) test-on-demand targets

Change-Id: I27f9e1b3e6a81b9e1efc9ecf993d9158c9f7c7d9
Signed-off-by: Tim Burke <tim.burke@gmail.com>

Author: tipabu

.zuul.yaml

@@ -37,10 +37,14 @@
       # on-demand pipeline used to test older (but still supported) versions of python,
       # as well as intermediate releases that the openstack-python3-jobs might skip
       jobs:
-        - openstack-tox-py37
+        - openstack-tox-py37:
+            nodeset: ubuntu-jammy
+            vars:
+              python_use_pyenv: True
         - openstack-tox-py38
         - openstack-tox-py39
         - openstack-tox-py311
+        - openstack-tox-py312
     check:
       jobs:
         - swiftclient-functional:

tox.ini

@@ -24,7 +24,7 @@ passenv = SWIFT_*
 commands =
     python -m flake8 swiftclient test
 
-[testenv:{py36,py37,py38}]
+[testenv:{py37,py38,py39}]
 # Drop the use of constraints; most dependencies have dropped support for
 # these versions already, and have updated their metadata to reflect that
 deps = -r{toxinidir}/requirements.txt