With this commit, we basically drop our scripts kali-run-britney.sh and
kali-prepare-data.sh, in favor of using run-standalone.sh.

To clarify, the script kali-run-britney.sh still exists, but all it does
is call run-standalone.sh and store/rotate the logs.

Refer to upstream commit 0f757223 from
sdelafond: this is when run-standalone.sh was introduced, along with
other scripts. In particular, scripts/debci-put.py used to be
Kali-specific, it was reworked to be more generic and is now provided by
upstream. Similarly, run-standalone.sh is a more generic approach that
does what kali-run-britney.sh and kali-prepare-data.sh used to do for
Kali.

With all that being said, run-standalone.sh is not exactly on par with
what we had in the Kali scripts, and not completely flexible enough, so
we still need to patch it a bit for our use-case.

Finally: note that, with this change, we lose support for the
--no-prepare argument in th...