Cannot create temporary combatants

[numberQ]

Describe the bug
Temporary combatants are not added to the initiative tracker after filling out the form and clicking 'Save'.

To Reproduce
Steps to reproduce the behavior:

1. Go to the combat tracker
2. Click '+ Add Temporary Combatant'
3. Fill out the form (does not matter what values are used)
4. Click 'Save'
5. Observe that no temporary combatant is added to the tracker

Expected behavior
After clicking 'Save', a temporary combatant should be added to the tracker.

Environment Info (please complete the following information):

• Foundry Version: 10.291
• Game System / Version: Pathfinder 2nd Edition 4.6.4
• CUB Version: 1.10.4
• Browser: software, not a browser
• OS: Windows 10

Additional context
Looks like there was a similar issue in an older version here: #545