Unconditionally enable i386 in the chroot for Ubuntu Desktop; the new installer doesn't handle enabling this at install time, and late enablement also misses us some recommends.

debian/changelog

@@ -1,3 +1,11 @@
+livecd-rootfs (2.832) UNRELEASED; urgency=medium
+
+  * Unconditionally enable i386 in the chroot for Ubuntu Desktop; the new
+    installer doesn't handle enabling this at install time, and late
+    enablement also misses us some recommends.
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Mon, 17 Apr 2023 16:51:13 -0700
+
 livecd-rootfs (2.831) lunar; urgency=medium
 
   * Use the correct path for the loop device.

live-build/ubuntu/hooks/020-canary-live.chroot_early

@@ -19,3 +19,10 @@ EOF
 cat <<EOF > /etc/initramfs-tools/conf.d/default-layer.conf
 LAYERFS_PATH=${PASS}.squashfs
 EOF
+
+if [ "$(dpkg --print-architecture)" = amd64 ]; then
+    echo "I: Enabling amd64 multiarch support on amd64"
+    dpkg --add-architecture i386
+
+    apt-get -y update
+fi