Update tox.ini

Author: auvipy

tox.ini

@@ -19,7 +19,7 @@ deps =
         django50: Django>=5.0,<5.1
         django51: Django>=5.1,<5.2
         django52: Django>=5.2,<6.0
-        django60: Django>=6.0a1,<6.1
+        django60: Django>=6.0b1,<6.1
         djangomain: https://github.com/django/django/archive/main.tar.gz
         -rrequirements/requirements-testing.txt
         -rrequirements/requirements-optionals.txt