### 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.
if (!selection.enabled && p_shift) {
		selection.start_column = caret_column;
	}
	if (!p_shift) {
		deselect();
	}
}
void LineEdit::shift_selection_check_post(bool p_shift) {
	if (p_shift) {
		selection_fill_at_caret();
	}
}
void LineEdit::set_caret_at_pixel_pos(int p_x) {