### 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?)
update_obj = true;
				} break;
				case Animation::TYPE_BLEND_SHAPE:
				case Animation::TYPE_VALUE: {
					if (name == "value") {
						Variant value = p_value;
						if (value.get_type() == Variant::NODE_PATH) {
							_fix_node_path(value, base_map[track]);
						}
						if (!setting) {
							setting = true;
							undo_redo->create_action(TTR("Animation Multi Change Keyframe Value"), UndoRedo::MERGE_ENDS);
						}
						Variant prev = animation->track_get_key_value(track, key);
						undo_redo->add_do_method(animation.ptr(), "track_set_key_value", track, key, value);
						undo_redo->add_undo_method(animation.ptr(), "track_set_key_value", track, key, prev);
						update_obj = true;
					}
				} break;
				case Animation::TYPE_METHOD: {
					Dictionary d_old = animation->track_get_key_value(track, key);
					Dictionary d_new = d_old.duplicate();
					bool mergeable = false;
					if (name == "name") {
						d_new["method"] = p_value;
					} else if (name == "arg_count") {
						Vector<Variant> args = d_old["args"];
						args.resize(p_value);
						d_new["args"] = args;
						change_notify_deserved = true;