fix: add apt-mark hold for openjdk-11-jdk (#92)

packer/jenkins-agents/stock/configure-jenkins.sh

@@ -15,7 +15,7 @@ apt install -y build-essential
 apt install -y python3 python3-pip
 pip install -q poetry launchpadlib
 apt install -y openjdk-17-jre-headless
-
+apt-mark hold openjdk-11-jdk
 #echo new cron into cron file
 echo '0 * * * * docker system prune --all --force --filter "until=1h"' | crontab