Knockouts don't have max_end_time

The code assumes that the end of the knockouts is not movable and
thus does not allow for any overrun.

Author: PeterJCLaw

schedule.yaml

@@ -55,7 +55,6 @@ match_periods:
   knockout:
   - start_time: 2024-04-14 14:15:00+01:00
     end_time: 2024-04-14 15:53:00+01:00
-    max_end_time: 2024-04-14 15:55:00+01:00
     description: Knockouts
 
 league: