add django 5.2a1 for initial testing

Author: auvipy

tox.ini

@@ -1,10 +1,10 @@
 [tox]
 envlist =
        {py38,py39}-{django42}
-       {py310}-{django42,django50,django51,djangomain}
-       {py311}-{django42,django50,django51,djangomain}
-       {py312}-{django42,django50,django51,djangomain}
-       {py313}-{django51,djangomain}
+       {py310}-{django42,django51,django52,djangomain}
+       {py311}-{django42,django51,django52,djangomain}
+       {py312}-{django42,django51,django52,djangomain}
+       {py313}-{django51,django52,djangomain}
        base
        dist
        docs
@@ -19,6 +19,7 @@ deps =
         django42: Django>=4.2,<5.0
         django50: Django>=5.0,<5.1
         django51: Django>=5.1,<5.2
+        django52: Django>=5.2a1,<6.0
         djangomain: https://github.com/django/django/archive/main.tar.gz
         -rrequirements/requirements-testing.txt
         -rrequirements/requirements-optionals.txt