fix: make filter_exclude_inactive and filter_surronding static

program/filters.py

@@ -162,7 +162,8 @@ class ScheduleFilterSet(filters.FilterSet):
         help_text="Excludes all schedules that don’t have timeslots in the future.",
     )
 
-    def filter_exclude_inactive(self, queryset: QuerySet, name: str, value: bool):
+    @staticmethod
+    def filter_exclude_inactive(queryset: QuerySet, _: str, value: bool):
         if not value:
             return queryset
         return queryset.filter(
@@ -213,7 +214,8 @@ class TimeSlotFilterSet(filters.FilterSet):
         help_text="Return only timeslots that belong to the specified show(s).",
     )
 
-    def filter_surrounding(self, queryset: QuerySet, name: str, value: datetime.datetime):
+    @staticmethod
+    def filter_surrounding(queryset: QuerySet, _: str, value: datetime.datetime):
         nearest_timeslots_in_future = (
             models.TimeSlot.objects.filter(start__gte=value)
             .order_by("start")