### Godot version

master ([06ccbfe](https://github.com/godotengine/godot/commit/06ccbfe8eec6e840db3df2360dc2804386f940b8))

### System information

PopOS 22.04

### Issue description

Sometimes the doc page is broken when the engine is closed and then restarted.
Closing the doc and opening it again fixes it.

![2023-05-27_22-15](https://github.com/godotengine/godot/assets/3624853/ed202a55-03e8-420a-bc1c-ccfc7f7cd02a)


### Steps to reproduce

- Open a documentation page for any node
- Restart Godot

### Minimal reproduction project

NA

EDIT : Added the commit hash @Calinou 
set_current_thread_safe_for_nodes(true);
	_process_line_caches();
	updating.store(false);
	call_deferred(SNAME("thread_end"));
}
void RichTextLabel::_thread_end() {
	set_physics_process_internal(false);
	if (is_visible_in_tree()) {
		queue_redraw();
	}
}
void RichTextLabel::_stop_thread() {
	if (threaded) {
		stop_thread.store(true);
		if (task != WorkerThreadPool::INVALID_TASK_ID) {
			WorkerThreadPool::get_singleton()->wait_for_task_completion(task);
			task = WorkerThreadPool::INVALID_TASK_ID;
		}
	}
}
int RichTextLabel::get_pending_paragraphs() const {