### Godot version

v4.1.stable.official [970459615]

### System information

Godot v4.1.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce MX330 (NVIDIA; 30.0.15.1169) - 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz (8 Threads)

### Issue description

Calling `RichTextLabel`'s `select_all` method has no visual indicator, but it must have one. 

### Steps to reproduce

- Add `RichTextLabel` node
- Set `selection_enabled` value to be `true`
- Call `$RichTextLabel.select_all() `method in `_ready`

### Minimal reproduction project

[RichTextLabel_bug.zip](https://github.com/godotengine/godot/files/12098913/RichTextLabel_bug.zip)

_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;
	}
	
	Vector<List<Item *>::Element *> subitem_to_remove;
	if (current_frame->lines[p_paragraph].from) {
		for (List<Item *>::Element *E = current_frame->lines[p_paragraph].from->E; E; E = E->next()) {