### 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.
case NOTIFICATION_RESIZED: {
			_fit_to_width();
			scroll_offset = 0.0;
			set_caret_column(get_caret_column());
		} break;
		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED:
		case NOTIFICATION_THEME_CHANGED: {
			_shape();
			queue_redraw();
		} break;
		case NOTIFICATION_TRANSLATION_CHANGED: {
			placeholder_translated = atr(placeholder);
			_shape();
			queue_redraw();
		} break;
		case NOTIFICATION_WM_WINDOW_FOCUS_IN: {
			window_has_focus = true;
			_validate_caret_can_draw();
			queue_redraw();
		} break;
		case NOTIFICATION_WM_WINDOW_FOCUS_OUT: {
			window_has_focus = false;
			_validate_caret_can_draw();
			queue_redraw();
		} break;
		case NOTIFICATION_INTERNAL_PROCESS: {
			if (caret_blink_enabled && caret_can_draw) {
				caret_blink_timer += get_process_delta_time();
				if (caret_blink_timer >= caret_blink_interval) {
					caret_blink_timer = 0.0;