### 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?)
multi_key_edit->animation = animation;
		multi_key_edit->animation_read_only = read_only;
		RBMap<int, List<float>> key_ofs_map;
		RBMap<int, NodePath> base_map;
		int first_track = -1;
		for (const KeyValue<SelectedKey, KeyInfo> &E : selection) {
			int track = E.key.track;
			if (first_track < 0) {
				first_track = track;
			}
			if (!key_ofs_map.has(track)) {
				key_ofs_map[track] = List<float>();
				base_map[track] = NodePath();
			}
			int key_id = E.key.key;
			if (key_id >= animation->track_get_key_count(track)) {
				_clear_key_edit();
				return; 
			}
			key_ofs_map[track].push_back(animation->track_get_key_time(track, E.key.key));
		}
		multi_key_edit->key_ofs_map = key_ofs_map;
		multi_key_edit->base_map = base_map;
		multi_key_edit->hint = _find_hint_for_track(first_track, base_map[first_track]);
		multi_key_edit->use_fps = timeline->is_using_fps();
		multi_key_edit->root_path = root;
		EditorNode::get_singleton()->push_item(multi_key_edit);
	}
}
void AnimationTrackEditor::_clear_selection_for_anim(const Ref<Animation> &p_anim) {