Also remove the tentative way compilation was expected to be fixed on
macOS ARM without really working.
In the future we will create universal binaries (which requires
compiling our prebuilt package for ARM as well), but until then we must
require the developer to pass `--cpu=darwin_x86_64` to the build
command when building on an ARM macOS platform like the M1. This will be
printed out explicitly now if it's not the case.
Providing `--dynamic_mode=fully` (for example setting it in
`local.bazelrc`) will now work.
All runfiles are now copied in the extractor pack: in dynamic mode,
those will be the executable and the dynamic libraries, while in static
mode only the executable will be part of the runfiles.
Setting the correct `LD_LIBRARY_PATH` in `qltest.sh` then allows to
run tests with this pakcage. If we need something more, we can switch to
a wrapper script in place of `extractor` in the future.
Notice that `LD_LIBRARY_PATH` is also set in static mode, but that has
no consequence.
