Removing a team from a league makes it difficult to remove them from events

**Describe the bug**
When a team is removed from a league, they no longer show up in the "League Members" page while adding teams to an event, which means if they had previously been added to the event you are unable to remove them from that page.

**To Reproduce**
Steps to reproduce the behavior:
1. Add all of the teams in a league to an event
2. Remove a team from the league
3. Open the event and go to Add/Edit teams
4. See that the team you removed is not present on the list of "League Members"
5. Play the event locally and generate a schedule
6. See that the removed team is still on the schedule

**Expected behavior**
I would expect removing a team from a league during the season would either:

1. Remove them from all future league events automatically
2. Still let them show up in the "League Members" list for the events that they had been added to, with something to indicate that they are no longer in the league.

If 1 is undesirable, 2 would make it easier to remove the team from the event and possibly would have caused me to notice that the team was still included before generating a bad schedule.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Device (please complete the following information):**
- OS: Windows 11
- Browser: Chrome
- Version: Current as of 12/7/24

**Additional context**
Add any other context about the problem here.