### Godot version

4.1.rc.custom_build. c83f912bc

### System information

Ubuntu 22.04 CI

### Issue description

When executing
```
extends Node
func _process(delta):

	var temp_variable35241 = RichTextLabel.new()
	add_child(temp_variable35241)
	temp_variable35241.set_fit_content(true)
	temp_variable35241.parse_bbcode("3188932498")
	temp_variable35241.queue_free()
```
this code freeze project in CI for at least 60 seconds

### Steps to reproduce

Above

### Minimal reproduction project

N/A
_stop_thread();
	MutexLock data_lock(data_mutex);
	main->_clear_children();
	current = main;
	current_frame = main;
	main->lines.clear();
	main->lines.resize(1);
	main->first_invalid_line.store(0);
	selection.click_frame = nullptr;
	selection.click_item = nullptr;
	deselect();
	current_idx = 1;
	current_char_ofs = 0;
	if (scroll_follow) {
		scroll_following = true;
	}
	if (fit_content) {
		update_minimum_size();
	}
}
void RichTextLabel::set_tab_size(int p_spaces) {
	if (tab_size == p_spaces) {
		return;
	}
	_stop_thread();
	tab_size = p_spaces;
	main->first_resized_line.store(0);
	queue_redraw();
}
int RichTextLabel::get_tab_size() const {