Please upgrade xorriso

Please upgrade xorriso

It appears that xorriso used to master the iso's is quite old:
Data preparer id: XORRISO-1.2.4 2012.07.20.130001, LIBISOBURN-1.2.4, LIBISOFS-1.2.4, LIBBURN-1.2.4

In debian-cd I see that CONF.sh overrides xorriso to
new_xorriso="/home/cdimage/xorriso/xorriso-1.2.4/xorriso/xorriso"

Which is actually old.

$ rmadison xorriso --arch amd64
 xorriso | 1.1.8-1 | precise | amd64
 xorriso | 1.3.2-1ubuntu1 | trusty | amd64
 xorriso | 1.4.2-4ubuntu1 | xenial/universe | amd64
 xorriso | 1.4.8-3 | bionic/universe | amd64
 xorriso | 1.5.0-1build1 | disco/universe | amd64
 xorriso | 1.5.0-1build1 | eoan/universe | amd64
 xorriso | 1.5.2-1 | focal/universe | amd64
 xorriso | 1.5.2-1 | groovy/universe | amd64

Please upgrade xorriso on the host to at least the one in xenial version 1.4.2-4ubuntu1

As the current 1.2.4 xorriso does not support varous --grub2-* options I want to use on amd64.

I guess we can start to use it only for groovy, if all good enable it for focal too.