Note that the URLs in these scripts are not only for information, but
they are also used as marker by pmbootstrap so it knows these are
compatible with 'pmbootstrap ci'. I just fixed the typo in the
pmbootstrap code as well and made a new release, use pmbootstrap 1.50.0
or above to have it recognize these scripts with 'pmbootstrap ci' again.
Adjust all CI scripts that make use of .ci/common.py to
'pmbootstrap ci'. Move all scripts that are not direct entry points to
running CI scripts to .ci/lib.
Comment out the dtb check, as it is failing. Apparently it didn't run
properly before. Let's fix this after this CI change is done.
Split out the grep for CHANGEME into a separate .ci/grep.sh script, as
it's not related to shellcheck and also there's another grep check that
I'll move there in a follow-up patch.