- remove a lot of hopefully / hardly confirmed, unused dependencies
- don't use crossbuild-essential-xxx; avoid the c++ compiler that comes with it, install gcc-only instead
- hostdeps: use `libc6-dev make dpkg-dev gcc` (without `g++`) instead of `build-essential`
- drop `btrfs-progs` and `f2fs-tools` (@TODO add in extension when/whereused)
- more: drop `cryptsetup` (@TODO add in extension when/whereused)
- don't be too quiet when doing apt-update for hostdeps