... to include a fix for
https://github.com/advisories/GHSA-c2h3-6mxw-7mvq .
(Note that Skopeo doesn't depend on the vulnerable code,
so this is primarily to avoid dependency checker warnings.)
Signed-off-by: Miloslav Trmač <mitr@redhat.com>
Temporarily vendor opencontainers/image-spec from a fork
to fix "id" value duplication, which is detected and
refused by gojsonschema now
( https://github.com/opencontainers/image-spec/pull/750 ).
Signed-off-by: Miloslav Trmač <mitr@redhat.com>