Temporarily disable gjs tests

gjs is not currently installable on buildds due to the glibc transition
and a long dependency chain involving systemd-shim being preferred over
systemd-sysv, which ends with libnih1 Depends: libc6 (<< 2.26).

debian/control

@@ -20,7 +20,6 @@ Build-Depends:
  e2fslibs-dev,
  elfutils,
  fuse,
- gjs [!sparc64],
  gobject-introspection,
  gtk-doc-tools <!nodoc>,
  libarchive-dev,