It aligns better with the Filesystem Heirarchy Standard[1] to put our
program-specific helper programs that are not intended to be executed by
the user of the application in $prefix/libexec or in whatever the
packager sets as the CMake equivalent. Namely, on Debian systems this
should be /usr/lib/Ladybird or similar.
[1] https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html#usrlibexec