### 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);
	if (current->type == ITEM_TABLE) {
		return;
	}
	ItemNewline *item = memnew(ItemNewline);
	item->line = current_frame->lines.size();
	_add_item(item, false);
	current_frame->lines.resize(current_frame->lines.size() + 1);
	_invalidate_current_line(current_frame);
	queue_redraw();
}
bool RichTextLabel::remove_paragraph(const int p_paragraph) {
	_stop_thread();
	MutexLock data_lock(data_mutex);
	if (p_paragraph >= (int)current_frame->lines.size() || p_paragraph < 0) {
		return false;