Bug#1038615: gcc-12-aarch64-linux-gnu: :amd64 package not installable on arm64

[Ian Gulliver <debian@flamingcow.io>]

Package: gcc-12-aarch64-linux-gnu
Version: 12.2.0-14cross1
Severity: normal
X-Debbugs-Cc: debian@flamingcow.io

When attempting to install gcc-12-aarch64-linux-gnu:amd64 on an arm64
system, conflicts prevent installation. I realize this is a silly thing
to want to do; this is attempt to simplify a cross-compile build, and
it works fine the other way (installing gcc-12-i686-linux-gnu:arm64 on
amd64).

The following packages have unmet dependencies:
 gcc-12-aarch64-linux-gnu:amd64 : Depends: binutils-aarch64-linux-gnu:amd64 (>= 2.40) but it is not going to be installed
                                  Depends: libgcc-12-dev-arm64-cross:amd64 (>= 12.2.0-14cross1) but it is not installable
E: Unable to correct problems, you have held broken packages.

-- System Information:
Debian Release: 12.0
  APT prefers stable-security
  APT policy: (500, 'stable-security'), (500, 'stable')
Architecture: arm64 (aarch64)
Foreign Architectures: amd64

Kernel: Linux 6.1.0-9-arm64 (SMP w/16 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled