### 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)

if (tag == "ol" || tag.begins_with("ol ") || tag == "ul" || tag.begins_with("ul ")) {
			if (txt.is_empty() && after_list_open_tag) {
				txt = "\n"; 
			}
			after_list_open_tag = true;
		} else {
			after_list_open_tag = false;
		}
		if (!txt.is_empty()) {
			add_text(txt);
		}
		after_list_close_tag = false;
		if (tag == "b") {
			
			in_bold = true;
			if (in_italics) {
				_push_def_font(BOLD_ITALICS_FONT);
			} else {
				_push_def_font(BOLD_FONT);
			}
			pos = brk_end + 1;
			tag_stack.push_front(tag);
		} else if (tag == "i") {
			
			in_italics = true;
			if (in_bold) {
				_push_def_font(BOLD_ITALICS_FONT);
			} else {
				_push_def_font(ITALICS_FONT);
			}