Improve Ubuntu 24.04 Booting

Increases ramdisk size, and sets cloud-config-url=/dev/null
to prevent hangs during the boot process.

Resolves: #1496

roles/netbootxyz/templates/menu/ubuntu.ipxe.j2

@@ -110,7 +110,7 @@ iseq ${os_arch} amd64 && set ubuntu_iso_url http://releases.ubuntu.com/${codenam
 iseq ${os_arch} arm64 && set ubuntu_iso_url http://cdimage.ubuntu.com/releases/${version_number}/release/ubuntu-${version_number}-live-server-${os_arch}.iso ||
 isset ${dhcp-server} && set netboot_params ip=dhcp url=${ubuntu_iso_url} || set netboot_params
 echo Loading Ubuntu Subiquity Network Installer...
-kernel ${kernel_url}vmlinuz root=/dev/ram0 ramdisk_size=1500000 ${netboot_params} ${install_params} {{ kernel_params }}
+kernel ${kernel_url}vmlinuz root=/dev/ram0 ramdisk_size=3500000 cloud-config-url=/dev/null ${netboot_params} ${install_params} {{ kernel_params }}
 initrd ${kernel_url}initrd
 echo
 echo MD5sums: