Preserve extended attributes in tarball

When specifying a tarball as output format, the extended attributes are
lost. This leads to programs like ping fail to run as normal user.

Therefore preserve the extended attributes when generating the tarball.

Signed-off-by: Benjamin Drung <benjamin.drung@cloud.ionos.com>

mmdebstrap

@@ -2836,7 +2836,7 @@ sub main() {
     }
 
     my $exitstatus = 0;
-    my @taropts = ('--sort=name', "--mtime=\@$mtime", '--clamp-mtime', '--numeric-owner', '--one-file-system', '-c', '--exclude=./dev');
+    my @taropts = ('--sort=name', "--mtime=\@$mtime", '--clamp-mtime', '--numeric-owner', '--one-file-system', '--xattrs', '-c', '--exclude=./dev');
 
     # disable signals so that we can fork and change behaviour of the signal
     # handler in the parent and child without getting interrupted