Update the tox environments

Python 3.9 is no longer supported on Django main (5.0).

Author: gvangool

tox.ini

@@ -4,7 +4,8 @@ envlist =
     py{36,38,39}-django21
     py{36,38,310}-django32
     py{38,39,310}-django40
-    py{39,310,311}-django{41,main}
+    py{39,310,311}-django{41,42}
+    py{310,311}-djangomain
 
 [testenv]
 deps =
@@ -18,4 +19,4 @@ deps =
     -r{toxinidir}/tests/requirements.txt
 commands =
     pip install -e .
-    pytest
+    pytest