Update dependency djangorestframework to v3.16.0

requirements.txt

@@ -12,7 +12,7 @@ django-split-settings==1.3.2
 django-tex==1.1.10
 django-timezone-field==7.1
 django_csp==3.8
-djangorestframework==3.15.2
+djangorestframework==3.16.0
 
 fontawesomefree==6.6.0  # Makes static files (css, fonts) available locally
 mysqlclient==2.2.7  # for production deployment