[sphinx-openapi] increased the version of sphinxcontrib-openapi to include new feature

dev.yml

@@ -42,4 +42,4 @@ dependencies:
     - django-post_office>=3.1,<3.2
     - drf-yasg>=1.16
     - djangorestframework>=3.9,<3.10
-    - sphinxcontrib-openapi>=0.4.0
+    - sphinxcontrib-openapi>=0.5.0