Add missing include to juce_linux_Windowing

[Scrumplex]

Without this the package wasn't building on Arch Linux. I assume that the recent update to GCC 12 on Arch Linux caused this.

Edit: I should add that this is needed for the use of std::exchange in https://github.com/sonosaurus/sonobus/blob/47ed1cfaaee634f26d206a0727cb089319b4ae8d/deps/juce/modules/juce_gui_basics/native/juce_linux_Windowing.cpp#L564-L573