bug#52908: 'tests/guix-system.sh' fails on aarch64-linux

[Leo Famulari]

The Guix test 'tests/guix-system.sh' fails on aarch64-linux, like this:

------
+ for example in gnu/system/examples/*.tmpl    
+ grep hurd              
+ echo gnu/system/examples/desktop.tmpl  
+ target=                          
+ guix system -n disk-image gnu/system/examples/desktop.tmpl                 
accepted connection from pid 23537, user nixbld                                 
                
guix system: warning: 'disk-image' is deprecated: use 'image' instead
spurious SIGPOLL               
spurious SIGPOLL                         
spurious SIGPOLL             
guix system: error: service 'xorg-server' provided more than once   
+ rm -f t-guix-system-22708 t-guix-system-error-22708 
/tmp/guix-build-guix-1.3.0-17.2a49ddb.drv-0/t-guix-system-22708/config.scm 
/tmp/guix-build-guix-1.3.0-17.2a49ddb.drv-0/t-guix-system-22708
/my-torrc                    
+ rmdir /tmp/guix-build-guix-1.3.0-17.2a49ddb.drv-0/t-guix-system-22708
FAIL tests/guix-system.sh (exit status: 1)
------

This manifests while building the 'guix' package itself. Specifically
this derivation:

/gnu/store/i8rjwl9fmm4b6icvry8l2wlz2dwq09ic-guix-1.3.0-17.2a49ddb.drv

... which is based on commit 9f6532c77d35603f5e5d190616e0c6b1740e82bd:

https://ci.guix.gnu.org/build/251537/details

It doesn't happen on x86_64-linux:

https://ci.guix.gnu.org/build/251564/details