### 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?)
} break;
		case Animation::TYPE_ANIMATION: {
			if (!node->is_class("AnimationPlayer")) {
				EditorNode::get_singleton()->show_warning(TTR("Animation tracks can only point to AnimationPlayer nodes."));
				return;
			}
			if (node == AnimationPlayerEditor::get_singleton()->get_player()) {
				EditorNode::get_singleton()->show_warning(TTR("AnimationPlayer can't animate itself, only other players."));
				return;
			}
			EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
			undo_redo->create_action(TTR("Add Track"));
			undo_redo->add_do_method(animation.ptr(), "add_track", adding_track_type);
			undo_redo->add_do_method(animation.ptr(), "track_set_path", animation->get_track_count(), path_to);
			undo_redo->add_undo_method(animation.ptr(), "remove_track", animation->get_track_count());
			undo_redo->commit_action();
		} break;
	}
}
void AnimationTrackEditor::_add_track(int p_type) {
	if (!root) {
		EditorNode::get_singleton()->show_warning(TTR("Not possible to add a new track without a root"));
		return;
	}
	adding_track_type = p_type;
	pick_track->popup_scenetree_dialog();
	pick_track->get_filter_line_edit()->clear();
	pick_track->get_filter_line_edit()->grab_focus();
}
void AnimationTrackEditor::_new_track_property_selected(String p_name) {