ubuntu-minimal should not depend on isc-dhcp-client

[Simon Déziel]

ubuntu-minimal already depends on `init` which depends on `systemd-sysv` which depends on `systemd` which comes with `systemd-networkd` that has a DHCP client in it.

Having the isc-dhcp-client package feels redundant.

# Additional information
$ lsb_release -rd
Description: Ubuntu Jammy Jellyfish (development branch)
Release: 22.04
$ apt-cache policy ubuntu-minimal
ubuntu-minimal:
  Installed: 1.478
  Candidate: 1.478
  Version table:
 *** 1.478 500
        500 http://archive.ubuntu.com/ubuntu jammy/main amd64 Packages
        100 /var/lib/dpkg/status

[Steve Langasek (vorlon)]

The isc-dhcp-client dependency exists to ensure support for network configuration from within an initramfs, for which systemd-networkd is not currently a replacement since we don't run systemd in the initramfs.

See also https://lists.ubuntu.com/archives/ubuntu-devel/2022-May/042080.html ff regarding the removal of isc-dhcp-client altogether in the future, but at least for now I would consider this request invalid since we don't have a replacement for it.

[Simon Déziel (sdeziel)]

Thanks for the explanation and pointer to the ML thread, makes sense to me now.