update ci script

ubuntu 22.04 use unified cgroup hierarchy, so we test cgroupv1 support
in uml

.umlrootfs/Dockerfile

@@ -1,13 +1,8 @@
-FROM debian:buster
-RUN apt-get update && apt-get install -y systemd rsh-redone-server ifupdown sudo kmod
+FROM debian:bullseye
+RUN apt-get update && apt-get install -y systemd rsh-redone-server ifupdown sudo kmod cgroup-tools systemd-sysv
 RUN echo "host" > /root/.rhosts && \
     chmod 600 /root/.rhosts && \
     /bin/echo -e "auto eth0\niface eth0 inet static\naddress 254.255.255.2/24" > /etc/network/interfaces.d/eth0 && \
     sed -i '/pam_securetty/d' /etc/pam.d/rlogin && \
     cp /usr/share/systemd/tmp.mount  /etc/systemd/system && \
     systemctl enable tmp.mount
-
-RUN echo "deb http://deb.debian.org/debian experimental main" >> /etc/apt/sources.list && \
-    apt-get update && \
-    apt-get install -y make && \
-    apt-get install -y -t experimental cgroup-tools