### 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)

ERR_FAIL_COND(p_frame == nullptr);
	ERR_FAIL_COND(p_line < 0 || p_line >= (int)p_frame->lines.size());
	Line &l = p_frame->lines[p_line];
	MutexLock lock(l.text_buf->get_mutex());
	RID t = l.text_buf->get_rid();
	int spans = TS->shaped_get_span_count(t);
	for (int i = 0; i < spans; i++) {
		ItemText *it = reinterpret_cast<ItemText *>((uint64_t)TS->shaped_get_span_meta(t, i));
		if (it) {
			Ref<Font> font = p_base_font;
			int font_size = p_base_font_size;
			ItemFont *font_it = _find_font(it);
			if (font_it) {
				if (font_it->font.is_valid()) {
					font = font_it->font;
				}
				if (font_it->font_size > 0) {
					font_size = font_it->font_size;
				}
			}
			ItemFontSize *font_size_it = _find_font_size(it);
			if (font_size_it && font_size_it->font_size > 0) {
				font_size = font_size_it->font_size;
			}
			TS->shaped_set_span_update_font(t, i, font->get_rids(), font_size, font->get_opentype_features());
			for (int j = 0; j < TextServer::SPACING_MAX; j++) {
				TS->shaped_text_set_spacing(t, TextServer::SpacingType(j), font->get_spacing(TextServer::SpacingType(j)));
			}