### Godot version

v4.1.beta.custom_build [d3651ea45]

### System information

Windows 11

### Issue description

![1](https://github.com/godotengine/godot/assets/28705694/15c14c93-7ad7-425a-8fb0-bef841b75527)

It's not possible to start text selection on a SpinBox when it's unfocused.

Note: After a bit of digging in the code, I found that clicking on a SpintBox doesn't trigger `SpinBox::gui_input` no matter if it's focused or not. However, releasing mouse left button does trigger the function.

### Steps to reproduce

See the gif.

### Minimal reproduction project

It's simple to reproduce.
CaretInfo caret = TS->shaped_text_get_carets(text_rid, ime_text.is_empty() ? caret_column : caret_column + ime_selection.x);
					if (using_placeholder || (caret.l_caret == Rect2() && caret.t_caret == Rect2())) {
						
						int h = theme_cache.font->get_height(theme_cache.font_size);
						int y = style->get_offset().y + (y_area - h) / 2;
						caret.l_dir = (rtl) ? TextServer::DIRECTION_RTL : TextServer::DIRECTION_LTR;
						switch (alignment) {
							case HORIZONTAL_ALIGNMENT_FILL:
							case HORIZONTAL_ALIGNMENT_LEFT: {
								if (rtl) {
									caret.l_caret = Rect2(Vector2(ofs_max, y), Size2(caret_width, h));
								} else {
									caret.l_caret = Rect2(Vector2(style->get_offset().x, y), Size2(caret_width, h));
								}
							} break;
							case HORIZONTAL_ALIGNMENT_CENTER: {
								caret.l_caret = Rect2(Vector2(size.x / 2, y), Size2(caret_width, h));
							} break;
							case HORIZONTAL_ALIGNMENT_RIGHT: {
								if (rtl) {
									caret.l_caret = Rect2(Vector2(style->get_offset().x, y), Size2(caret_width, h));
								} else {
									caret.l_caret = Rect2(Vector2(ofs_max, y), Size2(caret_width, h));
								}
							} break;
						}
						RenderingServer::get_singleton()->canvas_item_add_rect(ci, caret.l_caret, caret_color);
					} else {
						if (caret.l_caret != Rect2() && caret.l_dir == TextServer::DIRECTION_AUTO) {