### Godot version

4.0

### System information

Windows 11

### Issue description

So on my monitor with 2560x1440 resolution retrieved by the `DisplayServer.get_window_size` method shows 2562x1442, which I think is incorrect. A similar result returned by `get_viewport().size`. But it's become correct if the `Resizable` property is turned on.

![image](https://user-images.githubusercontent.com/3036176/212492776-5c09b12e-d25a-4951-8392-54f5a5e3bece.png)


### Steps to reproduce

Create the project, add a label to observe the resolution text, set the full-screen mode in the project settings, toggle off the `Resizable` property, and run the project.

### Minimal reproduction project

[TestResolution.zip](https://github.com/godotengine/godot/files/10418682/TestResolution.zip)

for (int i = 0; i < fcount; i++) {
				DragQueryFileW(hDropInfo, i, buf, buffsize);
				String file = String::utf16((const char16_t *)buf);
				files.push_back(file);
			}
			if (files.size() && !windows[window_id].drop_files_callback.is_null()) {
				Variant v = files;
				Variant *vp = &v;
				Variant ret;
				Callable::CallError ce;
				windows[window_id].drop_files_callback.callp((const Variant **)&vp, 1, ret, ce);
			}
		} break;
		default: {
			if (user_proc) {
				return CallWindowProcW(user_proc, hWnd, uMsg, wParam, lParam);
			}
		}
	}
	return DefWindowProcW(hWnd, uMsg, wParam, lParam);
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
	DisplayServerWindows *ds_win = static_cast<DisplayServerWindows *>(DisplayServer::get_singleton());
	if (ds_win) {
		return ds_win->WndProc(hWnd, uMsg, wParam, lParam);
	} else {
		return DefWindowProcW(hWnd, uMsg, wParam, lParam);
	}
}
void DisplayServerWindows::_process_activate_event(WindowID p_window_id, WPARAM wParam, LPARAM lParam) {