Actually uninstall the package

Author: Michael Vasseur

.github/jobs/chroot_checks.sh

@@ -44,7 +44,7 @@ cd /opt/domjudge/judgehost/bin || exit 1
 section_end chroot
 
 section_start "Show minimal chroot"
-apt-get install -y arch-test
+apt-get purge -y arch-test
 ./dj_make_chroot -a "$ARCH" | tee -a "$ARTIFACTS"/chroot.log
 section_end