Enable --init for podman container

We had some issues with signals/killing child processes, which was fixed by running sshd in a loop. However, using /bin/sh as PID1 is not ideal, as it might not reap dead processes or handle signal forwarding, so it's better to use a small init process, as we're running full-fledged long-term environment in a container, and not simple well-known service from the image itself.

Author: ilyaluk

bob/mkosi.extra/usr/bin/init-container.sh

@@ -12,6 +12,7 @@ SEARCHER_INPUT_CHANNEL=27017
 echo "Starting $NAME..."
 su -s /bin/sh searcher -c "cd ~ && podman run -d \
     --name $NAME --replace \
+    --init \
     -p ${SEARCHER_SSH_PORT}:22 \
     -p ${ENGINE_API_PORT}:${ENGINE_API_PORT} \
     -p ${EL_P2P_PORT}:${EL_P2P_PORT} \
@@ -82,4 +83,4 @@ su -s /bin/sh searcher -c "podman exec $NAME /bin/sh -c '
     echo \"18.221.59.61 backruns.tee-searcher.flashbots.net\" >> /etc/hosts &&
     echo \"3.15.88.156 backruns.tee-searcher.flashbots.net\" >> /etc/hosts &&
     echo \"52.207.17.217 fbtee.titanbuilder.xyz\" >> /etc/hosts
-'"
+'"