arch_boxes_sync: Pull the artifacts from GitLab's package registry

arch-boxes has decided to use GitLab's package registry instead of job artifacts[1].

[1] arch-boxes@d04c8274

roles/arch_boxes_sync/files/arch-boxes-sync.sh

@@ -30,7 +30,7 @@ readonly TMPDIR="$(mktemp --directory --tmpdir="/var/tmp")"
 trap "rm -rf \"${TMPDIR}\"" EXIT
 cd "${TMPDIR}"
 
-mkdir files
+mkdir "${LATEST_VERSION}"
 while IFS= read -r FILE; do
   FILE_CREATED_AT="$(jq -r .created_at <<< "${FILE}")"
   FILE_NAME="$(jq -r .file_name <<< "${FILE}")"
@@ -41,14 +41,11 @@ while IFS= read -r FILE; do
     continue
   fi
 
-  curl --silent --show-error --fail --output "files/${FILE_NAME}" "https://gitlab.archlinux.org/api/v4/projects/${PROJECT_ID}/packages/generic/${PACKAGE_NAME}/${LATEST_VERSION}/${FILE_NAME}"
+  curl --silent --show-error --fail --output "${LATEST_VERSION}/${FILE_NAME}" "https://gitlab.archlinux.org/api/v4/projects/${PROJECT_ID}/packages/generic/${PACKAGE_NAME}/${LATEST_VERSION}/${FILE_NAME}"
   sha256sum --quiet -c <<< "${FILE_SHA256} files/${FILE_NAME}"
   touch --no-create --date="@$(date -d "${FILE_CREATED_AT}" +%s)" "files/${FILE_NAME}"
 done < <(jq -c .[] <<< "${PACKAGE_FILES}")
 
-mkdir "${LATEST_VERSION}"
-mv files/* "${LATEST_VERSION}"
-
 for FILE in "${LATEST_VERSION}"/*; do
   if [[ $FILE == *${LATEST_VERSION:1}* ]]; then
     DEST="${FILE//-${LATEST_VERSION:1}}"