### 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);
	ERR_FAIL_COND(current->type == ITEM_TABLE);
	ERR_FAIL_COND(p_string.is_empty());
	ERR_FAIL_COND(p_font.is_null());
	ERR_FAIL_COND(p_size <= 0);
	ItemDropcap *item = memnew(ItemDropcap);
	item->text = p_string;
	item->font = p_font;
	item->font_size = p_size;
	item->color = p_color;
	item->ol_size = p_ol_size;
	item->ol_color = p_ol_color;
	item->dropcap_margins = p_dropcap_margins;
	_add_item(item, false);
}
void RichTextLabel::_push_def_font_var(DefaultFont p_def_font, const Ref<Font> &p_font, int p_size) {
	_stop_thread();
	MutexLock data_lock(data_mutex);
	ERR_FAIL_COND(current->type == ITEM_TABLE);
	ItemFont *item = memnew(ItemFont);
	item->def_font = p_def_font;
	item->variation = true;
	item->font = p_font;
	item->font_size = p_size;
	item->def_size = (p_size <= 0);
	_add_item(item, true);
}
void RichTextLabel::_push_def_font(DefaultFont p_def_font) {