Tests(tox): Add forgotten Python 3.13

Author: phdru

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.15
-envlist = py{27,34,35,36,37,38,39,310,311,312,py,py3},py{27,37,312}-flake8
+envlist = py{27,34,35,36,37,38,39,310,311,312,313,py,py3},py{27,37,312}-flake8
 
 # Base test environment settings
 [testenv]
@@ -11,12 +11,12 @@ commands =
 deps =
     -rdevscripts/requirements/requirements_tests.txt
 
-[testenv:py{27,34,35,36,37,38,39,310,311,312,py,py3}]
+[testenv:py{27,34,35,36,37,38,39,310,311,312,313,py,py3}]
 commands =
     {[testenv]commands}
     {envpython} -m pytest
 
-[testenv:py{27,34,35,36,37,38,39,310,311,312}-flake8]
+[testenv:py{27,34,35,36,37,38,39,310,311,312,313}-flake8]
 deps =
     flake8
     pytest < 7.0