hack/build-image: disable archive command for indexes

Ignore index targets if `--combined` is passed along with
`--archive=<dir>`.

Signed-off-by: John Mulligan <[email protected]>

Author: phlogistonjohn

hack/build-image

@@ -778,6 +778,8 @@ def push(cli, target):
 
 def archive(cli, target, location):
     """Write tarballs to archive location."""
+    if isinstance(target, TargetIndex):
+        return  # ignore indexes/manifests
     _autobuild(cli, target)
 
     eng = container_engine(cli)