This fixes this build error observed with clang and -stdlib=libc++:

../mpd-0.23.3/src/output/plugins/PipeWireOutputPlugin.cxx:661:55: error: implicit instantiation of undefined template 'std::array<std::byte, 64>'
        std::array<std::byte, MAX_CHANNELS * MAX_INTERLEAVE> buffer;
                                                             ^
/usr/include/c++/v1/__tuple:219:64: note: template is declared here
template <class _Tp, size_t _Size> struct _LIBCPP_TEMPLATE_VIS array;
                                                               ^