Update docker image removal script

.gitlab-ci.yml

@@ -44,11 +44,9 @@ build-image:
     - docker system df
     - docker system prune -f
     - |
-      docker images --format '{{.Repository}}:{{.Tag}} {{.ID}} {{.CreatedSince}}' | grep 'weeks' | while read -r line; do
-          image_id=$(echo $line | awk '{print $2}')
-          if ! docker ps -a --format '{{.Image}}' | grep -q $(echo $line | awk '{print $1}'); then
-              docker rmi $image_id
-          fi
+      docker images --format '{{.ID}} {{.CreatedSince}}' | grep -E 'weeks|months' | while read -r line; do
+          image_id=$(echo $line | awk '{print $1}')
+          docker rmi -f $image_id
       done