### 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)

}
	}
	Item *it_to = (p_line + 1 < (int)p_frame->lines.size()) ? p_frame->lines[p_line + 1].from : nullptr;
	for (Item *it = l.from; it && it != it_to; it = _get_next_item(it)) {
		switch (it->type) {
			case ITEM_TABLE: {
				ItemTable *table = static_cast<ItemTable *>(it);
				for (Item *E : table->subitems) {
					ERR_CONTINUE(E->type != ITEM_FRAME); 
					ItemFrame *frame = static_cast<ItemFrame *>(E);
					for (int i = 0; i < (int)frame->lines.size(); i++) {
						_update_line_font(frame, i, p_base_font, p_base_font_size);
					}
				}
			} break;
			default:
				break;
		}
	}
}
float RichTextLabel::_resize_line(ItemFrame *p_frame, int p_line, const Ref<Font> &p_base_font, int p_base_font_size, int p_width, float p_h) {
	ERR_FAIL_COND_V(p_frame == nullptr, p_h);
	ERR_FAIL_COND_V(p_line < 0 || p_line >= (int)p_frame->lines.size(), p_h);
	Line &l = p_frame->lines[p_line];
	MutexLock lock(l.text_buf->get_mutex());
	l.offset.x = _find_margin(l.from, p_base_font, p_base_font_size);
	l.text_buf->set_width(p_width - l.offset.x);
	PackedFloat32Array tab_stops = _find_tab_stops(l.from);
	if (!tab_stops.is_empty()) {
		l.text_buf->tab_align(tab_stops);