### 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.
Rect2 trect = Rect2(caret.l_caret.position.x - 2.5 * caret_width, caret.l_caret.position.y, 6 * caret_width, caret_width);
							trect.position += ofs;
							RenderingServer::get_singleton()->canvas_item_add_rect(ci, trect, caret_color);
						} else if (caret.l_caret != Rect2() && caret.t_caret != Rect2() && caret.l_dir != caret.t_dir) {
							
							float d = (caret.l_dir == TextServer::DIRECTION_LTR) ? 0.5 : -3;
							Rect2 trect = Rect2(caret.l_caret.position.x + d * caret_width, caret.l_caret.position.y + caret.l_caret.size.y - caret_width, 3 * caret_width, caret_width);
							trect.position += ofs;
							RenderingServer::get_singleton()->canvas_item_add_rect(ci, trect, caret_color);
							d = (caret.t_dir == TextServer::DIRECTION_LTR) ? 0.5 : -3;
							trect = Rect2(caret.t_caret.position.x + d * caret_width, caret.t_caret.position.y, 3 * caret_width, caret_width);
							trect.position += ofs;
							RenderingServer::get_singleton()->canvas_item_add_rect(ci, trect, caret_color);
						}
						caret.l_caret.position += ofs;
						caret.l_caret.size.x = caret_width;
						RenderingServer::get_singleton()->canvas_item_add_rect(ci, caret.l_caret, caret_color);
						caret.t_caret.position += ofs;
						caret.t_caret.size.x = caret_width;
						RenderingServer::get_singleton()->canvas_item_add_rect(ci, caret.t_caret, caret_color);
					}
				}
				if (!ime_text.is_empty()) {
					{
						
						Vector<Vector2> sel = TS->shaped_text_get_selection(text_rid, caret_column, caret_column + ime_text.length());
						for (int i = 0; i < sel.size(); i++) {
							Rect2 rect = Rect2(sel[i].x + ofs.x, ofs.y, sel[i].y - sel[i].x, text_height);
							if (rect.position.x + rect.size.x <= x_ofs || rect.position.x > ofs_max) {
								continue;