Try doing parallel downloads with curl

.gitlab-ci.yml

@@ -73,13 +73,15 @@ downloads:
   script:
     - set -exo pipefail
     - packer init sources
+    - files=""
     - |-
       for vars in $(find distros/ -name '*.pkrvars.hcl'); do
         file=$(echo var.iso.url | packer console -var-file=${vars} -config-type=hcl2 sources/)
-        pushd cache
+        files="${file} ${files}"
-        curl -O "${file}"
-        popd
       done
+      pushd cache
+      curl --parallel -L -O "${files}"
+      popd
 
 trigger:
   stage: trigger