There was an upstream change in DRF which as not been release yet

so only master till it is released.

see https://github.com/encode/django-rest-framework/pull/9527/files

Author: sliverc

tox.ini

@@ -2,7 +2,7 @@
 envlist =
     py{38,39,310,311,312}-django42-drf{314,315,master},
     py{310,311,312}-django{50,51}-drf{314,315,master},
-    py313-django51-drf{315,master},
+    py313-django51-drf{master},
     black,
     docs,
     lint