building Fails on Ubuntu Impish

The first failing commit was d209239 after merging the c++20 changed from #4803

/usr/bin/c++ -DHAVE_INET_ATON -DHAVE_INET_PTON -DHAVE_UNISTD_H -DMIXXX_BUILD_RELEASE -DNDEBUG -DPA_USE_ALSA -DQT_CONCURRENT_LIB -DQT_CORE_LIB -DQT_DBUS_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_NO_DEBUG -DQT_OPENGL_LIB -DQT_PRINTSUPPORT_LIB -DQT_QMLMODELS_LIB -DQT_QML_LIB -DQT_QUICKWIDGETS_LIB -DQT_QUICK_LIB -DQT_SQL_LIB -DQT_SVG_LIB -DQT_TABLET_SUPPORT -DQT_TESTCASE_BUILDDIR="\"/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu\"" -DQT_TESTLIB_LIB -DQT_USE_QSTRINGBUILDER -DQT_WIDGETS_LIB -DQT_X11EXTRAS_LIB -DQT_XML_LIB -DSFC_SUPPORTS_SET_COMPRESSION_LEVEL -D__BATTERY__ -D__BROADCAST__ -D__BULK__ -D__ENGINEPRIME__ -D__FFMPEG__ -D__HID__ -D__LILV__ -D__LINUX__ -D__MAD__ -D__MODPLUG__ -D__OPUS__ -D__QTKEYCHAIN__ -D__SNDFILE__ -D__SQLITE3__ -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -D__UNIX__ -D__VINYLCONTROL__ -D__WV__ -Dx86_64 -I"/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/mixxx-lib_autogen/include" -I"/<<PKGBUILDDIR>>/src" -I"/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/src" -isystem "/<<PKGBUILDDIR>>/lib/fidlib" -isystem "/<<PKGBUILDDIR>>/lib/googletest/googletest/include" -isystem "/<<PKGBUILDDIR>>/lib/portaudio" -isystem "/<<PKGBUILDDIR>>/lib/rigtorp/SPSCQueue/include" -isystem "/<<PKGBUILDDIR>>/lib/replaygain" -isystem "/<<PKGBUILDDIR>>/lib/reverb" -isystem /usr/include/glib-2.0 -isystem /usr/lib/x86_64-linux-gnu/glib-2.0/include -isystem "/<<PKGBUILDDIR>>/lib/libshout-idjc/include" -isystem "/<<PKGBUILDDIR>>/lib/kaitai" -isystem "/<<PKGBUILDDIR>>/lib/mp3guessenc-0.27.4" -isystem /usr/include/x86_64-linux-gnu/qt5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtConcurrent -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore -isystem /usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++ -isystem /usr/include/x86_64-linux-gnu/qt5/QtGui -isystem /usr/include/x86_64-linux-gnu/qt5/QtNetwork -isystem /usr/include/x86_64-linux-gnu/qt5/QtOpenGL -isystem /usr/include/x86_64-linux-gnu/qt5/QtWidgets -isystem /usr/include/x86_64-linux-gnu/qt5/QtPrintSupport -isystem /usr/include/x86_64-linux-gnu/qt5/QtQml -isystem /usr/include/x86_64-linux-gnu/qt5/QtQuickWidgets -isystem /usr/include/x86_64-linux-gnu/qt5/QtQuick -isystem /usr/include/x86_64-linux-gnu/qt5/QtQmlModels -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtSvg -isystem /usr/include/x86_64-linux-gnu/qt5/QtTest -isystem /usr/include/x86_64-linux-gnu/qt5/QtXml -isystem /usr/include/x86_64-linux-gnu/qt5/QtX11Extras -isystem /usr/include/x86_64-linux-gnu/qt5/QtDBus -isystem "/<<PKGBUILDDIR>>/lib/qm-dsp" -isystem "/<<PKGBUILDDIR>>/lib/qm-dsp/include" -isystem /usr/include/taglib -isystem /usr/include/libupower-glib -isystem /usr/include/lilv-0 -isystem /usr/include/opus -isystem "/<<PKGBUILDDIR>>/lib/hidapi/hidapi" -isystem /usr/include/libusb-1.0 -isystem "/<<PKGBUILDDIR>>/lib/xwax" -isystem /usr/include/wavpack -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -g -DNDEBUG -fvisibility=hidden -fvisibility-inlines-hidden -pipe -O3 -ffast-math -funroll-loops -fomit-frame-pointer -mtune=generic -Wall -Wextra -Woverloaded-virtual -Wfloat-conversion -Werror=return-type -Wformat=2 -Wformat-security -Wvla -Wundef -pthread -fPIC -Wno-unused-parameter -std=gnu++2a -o CMakeFiles/mixxx-lib.dir/src/effects/effectchain.cpp.o -c "/<<PKGBUILDDIR>>/src/effects/effectchain.cpp"
In file included from /usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentiteratekernel.h:49,
                 from /usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentfilterkernel.h:47,
                 from /usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentfilter.h:47,
                 from /usr/include/x86_64-linux-gnu/qt5/QtConcurrent/QtConcurrent:8,
                 from /<<PKGBUILDDIR>>/src/dialog/dlgreplacecuecolor.cpp:8:
/usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentthreadengine.h:250:50: error: invalid declarator before ‘*’ token
  250 | ThreadEngineStarter<void>(ThreadEngine<void> *_threadEngine)
      | ^
/usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentthreadengine.h:250:49: error: expected ‘)’ before ‘*’ token
  250 | ThreadEngineStarter<void>(ThreadEngine<void> *_threadEngine)
      | ~ ^~
      | )