Remove provision for missing fields on Hit (#4027)

Author: dhruvkb

api/api/serializers/base.py

@@ -16,9 +16,6 @@ def build_property_field(self, field_name, model_class):
         """
 
         klass, kwargs = super().build_property_field(field_name, model_class)
-        kwargs |= {
-            "allow_null": True,  # model computed properties are not present in ``Hit``
-        }
         if doc := getattr(model_class, field_name).__doc__:
             kwargs.setdefault("help_text", doc)
         return klass, kwargs

api/api/serializers/media_serializers.py

@@ -728,7 +728,7 @@ def to_representation(self, *args, **kwargs):
         # Ensure license is lowercase
         output["license"] = output["license"].lower()
 
-        if output["license_url"] is None:
+        if output.get("license_url") is None:
             output["license_url"] = get_license_url(
                 output["license"], output["license_version"]
             )