Revert "pmb.install.losetup: Run kpartx, losetup in chroot (MR 2430)"

This series breaks pmbootstrap, and that's not good[1]. A bug was filed about this (#2465 (closed)), and there have been multiple attempts to fix it (!2435 (closed) and !2436 (closed)). It kinda seems like we don't have time to fix/test this for a while longer, which is fine, but given the impact this bug has I think we should be revert this series until this issue is solved/tested.

1. pmb is broken in some specific cases, which means some workflows are broken. One example is that this breaks the pmaports CI, so no work can be done in pmaports.

changed the description

approved this merge request

lgtm, this mr doesn't prevent us from trying some alternative solution to this issue and it does fix an immediate breaking bug in CI.

merged

mentioned in issue #2465 (closed)

mentioned in merge request pmaports!5713 (merged)

mentioned in merge request !2435 (closed)

mentioned in merge request !2436 (closed)