fix: add libstdc++ CXXFLAGS, document with target subdir hack

fix: c++ include paths

The C include path has to be the latest! This is because
the cstdlib header uses #include_next <stdlib.h>, and
since the include of C headers comes first, stdlib.h is
not found!

fix: libstdc++ getentropy fix

The newlib does not expose getentropy in the final libraries,
but stil has it in the headers. That leads to configure thinking
getentropy is available and it will be used in the <random>.

feat: split arm 12.3 toolchain to non-nano and nano

fix: libstdc++ output lib path

chore: formatting

feat: add buildable libstdc++ to arm gcc toolchain 12.3

feat: add getdns and stubby

feat: arm toolchain 12.3.rel1

feat: add mpris-ctl, sequence-detector

feat: add spotify-qt package

fix: correctly replace with python 3.12

feat: add iamb

feat: add wlopm

feat: add dwl xwayland override

feat: add dwlmsg

feat: add dwl main branch

feat: add dmenu-wl

fix: wlroots0.18 patch for hwdata

Did not support DRM, because hwdata in Guix doesn't
support pkg-config. This should be resolved in guix.

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