greg.admin, greg.api: fix static analysis problems

Fixes: GREG-13

greg/admin.py

@@ -79,7 +79,7 @@ class PersonConsentAdmin(admin.ModelAdmin):
     def get_consent_name_en(self, obj):
         return obj.consent.consent_name_en
 
-    get_consent_name_en.short_description = "Consent name"
+    get_consent_name_en.short_description = "Consent name"  # type: ignore
 
 
 class OrganizationalUnitAdmin(admin.ModelAdmin):

greg/api/views/health.py

+from typing import (
+    Sequence,
+    Type,
+)
+
 from django.http import HttpResponse
 from drf_spectacular.utils import extend_schema
+from rest_framework.authentication import BaseAuthentication
+from rest_framework.permissions import BasePermission
 from rest_framework.status import HTTP_200_OK
 from rest_framework.views import APIView
 
@@ -7,12 +14,10 @@ from rest_framework.views import APIView
 class Health(APIView):
     """Health checks."""
 
-    authentication_classes = []
-    permission_classes = []
+    authentication_classes: Sequence[Type[BaseAuthentication]] = []
+    permission_classes: Sequence[Type[BasePermission]] = []
 
-    @extend_schema(
-        responses={200: str},
-    )
+    @extend_schema(responses={200: str})
     def get(self, request, *args, **kwargs):
         """Always gives a thumbs up by returning `OK` as plain text."""
         return HttpResponse("OK", content_type="text/plain", status=HTTP_200_OK)