Address lint remarks

AKModel/models.py

@@ -285,6 +285,7 @@ class Event(models.Model):
         start: datetime,
         end: datetime,
         slot_duration: timedelta,
+        *,
         slot_index: int = 0,
         constraints: set[str] | None = None,
     ) -> Generator[TimeslotBlock, None, int]:

AKModel/views/ak.py

 import json
-from datetime import datetime
 from typing import List
 
 from django.contrib import messages