gitlab_runner: Reduce libvirt-executor noise in the job log

This removes 13 instances of [1] and 1 instance of the IP address from
the job log.

The latter was fixed by no longer waiting for SSH in the "run" stage,
which is unnecessary as we wait for SSH in the "prepare" stage.

[1] Warning: Permanently added '192.168.122.xxx' (ED25519) to the list of known hosts.

roles/gitlab_runner/files/libvirt-executor

@@ -10,6 +10,7 @@ ssh() {
     -o ServerAliveInterval=15 \
     -o UserKnownHostsFile=/dev/null \
     -o StrictHostKeyChecking=off \
+    -o LogLevel=error \
     "root@${1}" "${@:2}"
 }
 
@@ -39,7 +40,6 @@ wait_for_ssh() {
       sleep 1
       continue
     fi
-    printf "%s" "${ip}"
     return 0
   done
   echo 'Waited 30 seconds for VM to start, exiting...'
@@ -68,7 +68,7 @@ prepare() {
 # https://docs.gitlab.com/runner/executors/custom.html#run
 run() {
   local ip
-  ip="$(wait_for_ssh "$(vm_name)")"
+  ip="$(vm_ip "$(vm_name)")"
   ssh "${ip}" bash < "${1}" || exit "${BUILD_FAILURE_EXIT_CODE:-1}"
 }