Drop references to ubuntu-dvd, obsolete since precise.

debian/changelog

@@ -9,6 +9,7 @@ livecd-rootfs (23.10.33) UNRELEASED; urgency=medium
   * ubuntu-unity-live task exists, use it also instead of hard-coded list of
     packages.
   * live-build/auto/config: various refactors to eliminate code duplication
+  * Drop references to ubuntu-dvd, obsolete since precise.
 
  -- Steve Langasek <steve.langasek@ubuntu.com>  Wed, 06 Sep 2023 11:23:17 -0700
 

live-build/auto/config

@@ -678,7 +678,7 @@ if ! [ -e config/germinate-output/structure ]; then
 fi
 
 case $PROJECT in
-	ubuntu|ubuntu-dvd)
+	ubuntu)
 
 		case ${SUBPROJECT:-} in
 			legacy)
@@ -1200,11 +1200,6 @@ if [ "$PREINSTALLED" != "true" ] && [ "$PASSES_TO_LAYERS" != "true" ] && [ "$LIV
 fi
 
 case $PROJECT in
-	ubuntu-dvd)
-		add_task install ubuntu-usb
-		add_task live ubuntu-usb-live
-		;;
-
 	*-dvd)
 		add_task live "$PROJECT-live"
 		;;