MT#64132 Update grml-live to version 0.56.0

Lots of changes took place in between v0.55.1 and v0.56.0 upstream[1].
To ensure to follow upstream changes, let's make sure our configuration
avoids relying on features that are going to be dropped in upcoming
versions.

[1] FTR (ignoring history as of 29b672db26d2783cfb0cce13ab18bddf37f1fdc1
  since that's a history merge of grml-hostname grml-scripts,
  see https://github.com/grml/grml-live/pull/495):

  % git log --oneline --no-merges v0.55.1..v0.56.0 ^29b672db26d2783cfb0cce13ab18bddf37f1fdc1
  5074e157 (tag: v0.56.0) Update changelog for 0.56.0 release
  695bfb20 grub: do not load bochs driver on UEFI platform
  8547ebc2 Revert "SW: drop grml-paste"
  0b75d3b9 d/control: Set X-Style: black
  92b66115 (pull-requests/499) caps-ctrl: fix shellcheck issues
  46d83be7 caps-ctrl: replace einfo/error/eend
  98481d90 caps-ctrl: inline check4progs from script-functions
  7a485c8f caps-ctrl: switch from zsh to bash
  ab43de11 Import caps-ctrl script from grml-scripts
  42e80074 (pull-requests/496) CI: rename artifacts for PRs
  5bde106e (pull-requests/498) grml-live: set GRML_LIVE_VERSION to git info when running from source
  e4b2aa33 (pull-requests/497) SW: remove grml-scripts from GRMLBASE
  bb3f8224 (pull-requests/495) grml-hostname: fix shellcheck issues
  8c6ece92 GRMLBASE: install grml-hostname
  4a593462 grml-hostname: inline check4root from script-functions
  dbc2fee9 (pull-requests/494) Drop leftover mysql support
  d12595b0 Drop leftover postfix support
  a3812da9 (pull-requests/490) DHCP client: support $HOSTNAME in dhcpcd.conf
  510eb8b8 GRMLBASE: merge 34-hosts and 35-network
  7b9bdae1 DHCP client: set hostname_default=grml
  e2dc4732 (pull-requests/460) grub: limit default max resolution
  8df5b308 DHCP client: remove isc-dhcp-client hostname hook script
  acb3985c (pull-requests/489, origin/zeha/grub_video_mods) grub: load video modules only on platforms where they exist
  c26633e9 (pull-requests/488, origin/mika/endk, mika/endk) /etc/locale.gen: add en_DK.UTF-8 as used within our default locales
  d9c87610 (pull-requests/487, origin/zeha/grub-fb-only-bios) grub: merge Disable Framebuffer and Disable Video Kernel Mode Setting options
  74585e44 (pull-requests/486, origin/zeha/dhcpcd-hwaddr) DHCP client: use hardware/ethernet address as identification
  86abd4bc (pull-requests/484) grub: drop loading of efi_uga module
  3e4c53a5 (pull-requests/459, origin/grublegacyboot) Use GRUB 2 for BIOS boot instead of ISOLINUX
  b4bfd616 (pull-requests/482) Use en_DK.UTF-8 as new default for LC_TIME
  1c456802 (pull-requests/481) 45-grub-images: drop efi_uga
  39770c67 (pull-requests/480) SW: add grml-terminalserver (and deps) on ARM64
  d0f622e8 (pull-requests/478) SW: drop grml-paste
  3bf80f26 (pull-requests/476, origin/mika/shellcheck) scripts/forensic-mark-readonly: fix POSIX issue reported by shellcheck
  3d138ca7 (pull-requests/475, origin/zeha/cleanup-wm-ng) Remove wm-ng (fluxbox wrapper) leftovers
  5c759406 (pull-requests/474) cheatcodes: drop "dmraid" and "nodmraid" options
  a3f5c838 cheatcodes: drop "grub" option
  0cfabe11 (pull-requests/473) grub: install unicode2.pf into correct place
  b9016282 (pull-requests/471) grml-live: fully remove BOOT_METHOD option
  2dcbbd49 (pull-requests/469, origin/zeha/sw-dupe-grub, github/zeha/sw-dupe-grub) SW: remove duplicated grub-pc-bin from GRML_FULL
  f9aa6bde (pull-requests/470, origin/zeha/grubtheme, github/zeha/grubtheme) grub/header.cfg: clean up theme init
  95884073 (pull-requests/468, origin/zeha/corezfs, github/zeha/corezfs) grub core.img: add zfs modules, drop reiserfs
  f1e14112 (pull-requests/467) build-driver/build disable apt script warning
  da51d6b2 (pull-requests/466, origin/mika/grubsb) GRUB: adjust loadfont usage for Secure Boot mode
  7f73470d (pull-requests/419) scripts/forensic-mark-readonly: Add support for loop devices
  f1cac02c (pull-requests/465) Use Debian packages for Secure Boot
  791a98cc Drop deprecated ubuntu approach for Secure Boot
  2a13a02c (pull-requests/464, origin/mika/virtio_gpu, mika/virtio_gpu) Add virtio_gpu to initramfs for proper console on arm64 in libvirt/qemu
  bf7ef990 (pull-requests/461, origin/zeha/memtest8, github/zeha/memtest8) GRMLBASE: follow rename of binaries in memtest+ 8.00
  614d030d (pull-requests/458) Import grml-lock from grml-scripts
  2eca5e96 Import grml-soundtest from grml-scripts
  04f2db8d Split "blacklist" program into "blacklist" and "unblacklist"
  c10e9d7c Import blacklist from grml-scripts
  9c80a720 Import grml2ram from grml-scripts
  1f09cd8d Import random-hostname from grml-scripts
  b6b749ed Import grml-resolution from grml-scripts
  cacea3da (pull-requests/457, origin/mika/passwd, mika/passwd) Rework password handling to unify random password generation
  929e2759 Random password generation: improve password usage
  d7137135 Random password generation: ignore write errors from tr
  b1d85652 (pull-requests/456, origin/grmlinfo) grml-info: convert to bash, drop script-functions usage
  16e403f7 Import grml-info from grml-scripts
  6813a6a0 (pull-requests/455) generate-changes-list: Do not list merge commits in changelog
  1352ed86 scripts/forensic-mark-readonly: Add support for devices with multiple parents
  d3611ffc scripts/forensic-mark-readonly: Fix properly finding the parent of a device-mapper device
  4c945efe scripts/forensic-mark-readonly: Do not depend on printf
  817d4047 scripts/forensic-mark-readonly: Fix not checking for block device in READONLY_IGNORE
  1a94f95e scripts/forensic-mark-readonly: Fix not setting to readonly when no parent

Change-Id: Iaa6e446e2a82dde3a083a7125803cb886663066a

grml_build/Dockerfile

@@ -6,7 +6,7 @@ FROM docker.mgm.sipwise.com/sipwise-trixie:latest
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT=2026-01-30
+ENV REFRESHED_AT=2026-04-29
 
 # tools for building and testing
 RUN apt-get update && apt-get install --assume-yes --no-install-recommends \
@@ -36,7 +36,7 @@ RUN apt-get update && apt-get install --assume-yes --no-install-recommends \
 # base build tools
 WORKDIR /code/
 
-RUN git clone -b 'v0.55.1' --single-branch --depth 1 https://github.com/grml/grml-live
+RUN git clone -b 'v0.56.0' --single-branch --depth 1 https://github.com/grml/grml-live
 
 WORKDIR /code/grml-live