Disable ext4 metadata_csum_seed for Debian releases older than bookworm

Disable ext4 metadata_csum_seed for Debian releases older than bookworm

As of e2fsprogs v1.43 and Linux kernel v4.4 the ext4 file system supports
the new metadata_csum_seed feature (which allows the file system UUID to
be modified without needing to update all of the file system metadata).
Also see https://bugs.debian.org/1031325

Starting with e2fsprogs v1.47 this new metadata_csum_seed feature gets
enabled by default. When installing an older Debian release this might
cause problems because it's not fully supported yet, see e.g. the GRUB
failure documented as #866603.

To keep the behavior identical to Debian, we do not enable the
metadata_csum_seed feature for Debian releases before bookworm.  This is
relevant for us, as grml-debootstrap might be running from a more recent
Debian release (like a Debian testing/unstable based Grml live system).

We check for the e2fsprogs version as versions before 1.43 didn't support
the metadata_csum_seed option yet.

Closes: #1031416
Closes: https://github.com/grml/grml-debootstrap/issues/204