greg.api.urls: fix url deprecation warnings

django.conf.urls.url has been deprecated in favour of django.urls.re_path,
which has matching behaviour.

This silences two warnings during the test run.

Fixes: GREG-14

greg/api/urls.py

-from django.conf.urls import url
-from django.urls import path
+from django.urls import (
+    path,
+    re_path,
+)
 from rest_framework.routers import DefaultRouter
-from drf_spectacular.views import SpectacularAPIView, SpectacularSwaggerView
+from drf_spectacular.views import (
+    SpectacularAPIView,
+    SpectacularSwaggerView,
+)
 
-from greg.api.views.person import PersonViewSet, PersonRoleViewSet
+from greg.api.views.person import (
+    PersonRoleViewSet,
+    PersonViewSet,
+)
 from greg.api.views.role import RoleViewSet
 from greg.api.views.health import Health
 
+
 router = DefaultRouter()
 router.register(r"persons", PersonViewSet, basename="person")
 router.register(r"roles", RoleViewSet, basename="role")
@@ -21,12 +30,12 @@ urlpatterns += [
         name="swagger-ui",
     ),
     path("health/", Health.as_view()),
-    url(
+    re_path(
         r"^persons/(?P<person_id>[0-9]+)/roles/$",
         PersonRoleViewSet.as_view({"get": "list"}),
         name="person_role-list",
     ),
-    url(
+    re_path(
         r"^persons/(?P<person_id>[0-9]+)/roles/(?P<id>[0-9]+)/$",
         PersonRoleViewSet.as_view({"get": "retrieve"}),
         name="person_role-detail",