Add Django 5.1 and DRF 3.15 to CI

Author: oxan

tox.ini

@@ -1,10 +1,10 @@
 [tox]
 isolated_build = True
 envlist =
-    py{38,39,310,311}-django{32}-drf{311,312,313,314,master}
-    py{38,39,310,311}-django{40}-drf{313,314,master}
-    py{38,39,310,311,312,313}-django{41,42}-drf{314,master}
-    py{310,311,312,313}-django{50}-drf{314,master}
+    py{38,39,310,311}-django{32}-drf{311,312,313,314,315,master}
+    py{38,39,310,311}-django{40}-drf{313,314,315,master}
+    py{38,39,310,311,312,313}-django{41,42}-drf{314,315,master}
+    py{310,311,312,313}-django{50,51}-drf{314,315,master}
 
 [gh-actions]
 python =
@@ -23,10 +23,12 @@ deps =
     django41: Django>=4.1,<4.2
     django42: Django>=4.2,<5.0
     django50: Django>=5.0,<5.1
+    django51: Django>=5.1,<5.2
     drf311: djangorestframework>=3.11,<3.12
     drf312: djangorestframework>=3.12,<3.13
     drf313: djangorestframework>=3.13,<3.14
     drf314: djangorestframework>=3.14,<3.15
+    drf315: djangorestframework>=3.15,<3.16
     drfmaster: https://github.com/encode/django-rest-framework/archive/master.tar.gz
 commands =
     coverage run -a manage.py test