Switch testing to Antelope testing runtime

Updating the testing template to Antelope testing runtime:
https://governance.openstack.org/tc/reference/runtimes/2023.1.html

Change-Id: I0c7e1497243c74a7c4e5bedbb3c94c80794490e9

.zuul.yaml

@@ -11,8 +11,7 @@
         - openstack-tox-py37
         - openstack-tox-py38
         - openstack-tox-py39
-        - openstack-tox-py310:
-            voting: false
+        - openstack-tox-py310
     gate:
       jobs:
         - openstack-tox-pep8
@@ -21,3 +20,4 @@
         - openstack-tox-py37
         - openstack-tox-py38
         - openstack-tox-py39
+        - openstack-tox-py310

setup.cfg

@@ -20,6 +20,7 @@ classifier =
     Programming Language :: Python :: 3.7
     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
 

test-requirements.txt

@@ -10,3 +10,4 @@ python-subunit>=0.0.18
 oslotest>=1.10.0 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0
 testscenarios>=0.4
+pymysql

tox.ini

@@ -9,7 +9,10 @@ basepython = python3
 usedevelop = True
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/test-requirements.txt
+deps =
+    -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -r{toxinidir}/requirements.txt
+    -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
 
 [testenv:pep8]