### 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);
	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) {