Revert "create_disk: add version field to aleph file"

This reverts commit c2d37f4.

We found an issue with this and need to revert it for now:
coreos/bootupd#585 (comment)

mantle/cmd/kola/testiso.go

@@ -174,7 +174,7 @@ StandardError=kmsg+console
 ExecStart=/bin/sh -c "journalctl -t coreos-installer-service | /usr/bin/awk '/[Dd]ownload/ {exit 1}'"
 ExecStart=/bin/sh -c "/usr/bin/udevadm settle"
 ExecStart=/bin/sh -c "/usr/bin/mount /dev/disk/by-label/root /mnt"
-ExecStart=/bin/sh -c "/usr/bin/jq -er '.[\"version\"] == \"%s\"' /mnt/.coreos-aleph-version.json"
+ExecStart=/bin/sh -c "/usr/bin/jq -er '.[\"build\"] == \"%s\"' /mnt/.coreos-aleph-version.json"
 ExecStart=/bin/sh -c "/usr/bin/jq -er '.[\"ostree-commit\"] == \"%s\"' /mnt/.coreos-aleph-version.json"
 [Install]
 RequiredBy=coreos-installer.target

src/create_disk.sh

@@ -386,11 +386,6 @@ test -d "${deploy_root}" || (echo "failed to find $deploy_root"; exit 1)
 #
 # build: The coreos-assembler build ID; today we support
 # having the same ostree commit in different image builds.
-# version: same value as build for now, even though version is
-# not exactly the same as build ID, this will ease
-# transition to using osbuild where it's defined
-# appropriately and build: isn't there:
-# https://github.com/osbuild/osbuild/pull/1475
 # ref: The ostree ref used; useful for cross-checking.
 # ostree-commit: Similar to `ref`; one can derive this from looking
 # at the coreos-assembler builds, but it's very
@@ -400,7 +395,6 @@ test -d "${deploy_root}" || (echo "failed to find $deploy_root"; exit 1)
 cat > $rootfs/.coreos-aleph-version.json << EOF
 {
  "build": "${buildid}",
- "version": "${buildid}",
  "ref": "${ref}",
  "ostree-commit": "${commit}",
  "imgid": "${imgid}"