### Godot version

4.0.dev (c309de53997feff3286295fb2d71657f112a15db)

### System information

Linux, Nvidia, Vulkan

### Issue description

Editor segfaults when certain conditions are met when using the AnimationPlayer editor.

### Steps to reproduce

1. Create multiple animations, saved into a animation collection
2. Open an existing animation, then make a new empty animation
3. Change from seconds to fps, or add a new property to animate ()
4. Editor crashes

NOTE: It is slightly random and I have not found a perfect repro

### Minimal reproduction project

N/A (TBD?)
bool update_obj = false;
	bool change_notify_deserved = false;
	for (const KeyValue<int, List<float>> &E : key_ofs_map) {
		int track = E.key;
		for (const float &key_ofs : E.value) {
			int key = animation->track_find_key(track, key_ofs, Animation::FIND_MODE_APPROX);
			ERR_FAIL_COND_V(key == -1, false);
			String name = p_name;
			if (name == "easing") {
				float val = p_value;
				float prev_val = animation->track_get_key_transition(track, key);
				EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
				if (!setting) {
					setting = true;
					undo_redo->create_action(TTR("Animation Multi Change Transition"), UndoRedo::MERGE_ENDS);
				}