### 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 
_stop_thread();
	MutexLock data_lock(data_mutex);
	ERR_FAIL_COND(current->type == ITEM_TABLE);
	ERR_FAIL_COND(p_columns < 1);
	ItemTable *item = memnew(ItemTable);
	item->columns.resize(p_columns);
	item->total_width = 0;
	item->inline_align = p_alignment;
	item->align_to_row = p_align_to_row;
	for (int i = 0; i < (int)item->columns.size(); i++) {
		item->columns[i].expand = false;
		item->columns[i].expand_ratio = 1;
	}
	_add_item(item, true, false);
}
void RichTextLabel::push_fade(int p_start_index, int p_length) {
	_stop_thread();
	MutexLock data_lock(data_mutex);
	ItemFade *item = memnew(ItemFade);
	item->starting_index = p_start_index;
	item->length = p_length;
	_add_item(item, true);
}
void RichTextLabel::push_shake(int p_strength = 10, float p_rate = 24.0f, bool p_connected = true) {