Fix authorized_keys for root runners

runner_scripts/root/run.sh

@@ -38,7 +38,7 @@ id -u "$AUTH_USER" >/dev/null 2>&1 || error "User $AUTH_USER does not exist"
 
 ## Use a key pair to authenticate the user (private key has to be set as a GitLab CI/CD variable)
 AUTH_KEY=$CUSTOM_ENV_AUTH_KEY
-AUTH_PUB=$AUTH_USER_HOME/gitlab-runner/authorized_keys
+AUTH_PUB=/etc/gitlab-runner/authorized_keys
 
 (
 while read -r PUB