Drop code only used for d-i based ubuntu-server images, no longer supported.

debian/changelog

@@ -21,6 +21,8 @@ livecd-rootfs (23.10.33) UNRELEASED; urgency=medium
   * Remove unnecessary arch guarding of the UbuntuStudio kernel selection:
     we only build this image on amd64 (the arch checking is from i386 days),
     and the lowlatency kernel also exists on arm64.
+  * Drop code only used for d-i based ubuntu-server images, no longer
+    supported.
 
  -- Steve Langasek <steve.langasek@ubuntu.com>  Wed, 06 Sep 2023 11:23:17 -0700
 

live-build/auto/config

@@ -1359,13 +1359,6 @@ EOF
 		;;
 esac
 
-if [ $PROJECT = ubuntu-server ] && [ "${SUBPROJECT:-}" != live ]; then
-	cat > config/hooks/100-remove-fstab.chroot <<EOF
-#! /bin/sh
-rm -f /etc/fstab
-EOF
-fi
-
 if [ $PROJECT != ubuntu-cpc ]; then
 	cat > config/hooks/100-preserve-apt-prefs.chroot <<\EOF
 #! /bin/sh -ex