Godot 4.3 Animationplayer crash after adding keyframe

### Tested versions

4.3.stable.mono.official

### System information

Godot v4.3.stable.mono - Windows 10.0.26100 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4090 Laptop GPU (NVIDIA; 32.0.15.7216) - AMD Ryzen 9 7945HX3D with Radeon Graphics (32 Threads)

### Issue description

(git enabled, but not used)
Just start a 3rd animation with animationplayer, just added first key frame, then Godot crashed. After that Every time I access Godot, I can get into the project, but the moment I click on the animationplayer, Godot crashes again. Remove .godot in project folder, rebuilding does not help. Close and restart godot and Visual studio code version 1.97.2 does not help. It always crashes when clicking on the animation player.

The project is zipped

### Steps to reproduce

- just open the project
- click on animation player , of the player scene. Afther that it will crash.

### Minimal reproduction project (MRP)

[project-with-error_godot.zip](https://github.com/user-attachments/files/18790946/project-with-error_godot.zip)