Follow-up to #2272: subdevice_role should not be required

netbox/dcim/api/serializers.py

@@ -284,7 +284,7 @@ class NestedDeviceTypeSerializer(serializers.ModelSerializer):
 
 
 class WritableDeviceTypeSerializer(CustomFieldModelSerializer):
-    subdevice_role = ChoiceFieldSerializer(choices=SUBDEVICE_ROLE_CHOICES, allow_null=True)
+    subdevice_role = ChoiceFieldSerializer(choices=SUBDEVICE_ROLE_CHOICES, allow_null=True, required=False)
 
     class Meta:
         model = DeviceType