ci: purge droplet-agent in packer cleanup script

dev/packer/scripts/900-cleanup.sh

@@ -14,16 +14,13 @@ if [[ ! -d /tmp ]]; then
 fi
 chmod 1777 /tmp
 
-if [ -n "$(command -v yum)" ]; then
-  yum update -y
-  yum clean all
-elif [ -n "$(command -v apt-get)" ]; then
-  export DEBIAN_FRONTEND=noninteractive
-  apt-get -y update
-  apt-get -o Dpkg::Options::="--force-confold" upgrade -q -y --force-yes
-  apt-get -y autoremove
-  apt-get -y autoclean
-fi
+export DEBIAN_FRONTEND=noninteractive
+apt-get -y update
+apt-get -o Dpkg::Options::="--force-confold" upgrade -q -y --force-yes
+apt-get purge droplet-agent
+rm -rf /opt/digitalocean
+apt-get -y autoremove
+apt-get -y autoclean
 
 rm -rf /tmp/* /var/tmp/*
 history -c