### 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)

_normalize_subtags(subtag_b);
						if (subtag_b.size() == 2) {
							Color color1 = Color::from_string(subtag_b[0], fallback_color);
							Color color2 = Color::from_string(subtag_b[1], fallback_color);
							set_cell_row_background_color(color1, color2);
						}
						if (subtag_b.size() == 1) {
							Color color1 = Color::from_string(subtag_a[1], fallback_color);
							set_cell_row_background_color(color1, color1);
						}
					} else if (subtag_a[0] == "padding") {
						Vector<String> subtag_b = subtag_a[1].split(",");
						_normalize_subtags(subtag_b);
						if (subtag_b.size() == 4) {
							set_cell_padding(Rect2(subtag_b[0].to_float(), subtag_b[1].to_float(), subtag_b[2].to_float(), subtag_b[3].to_float()));
						}
					}
				}
			}
			pos = brk_end + 1;
			tag_stack.push_front("cell");
		} else if (tag == "u") {
			
			push_underline();
			pos = brk_end + 1;
			tag_stack.push_front(tag);
		} else if (tag == "s") {
			
			push_strikethrough();
			pos = brk_end + 1;