osbase/oci: add package

This adds the oci package, which contains types and tools for working
with OCI images.

Change-Id: Ie2a1d82c7ac007f5d1ad47666880dbf8a8bd931d
Reviewed-on: https://review.monogon.dev/c/monogon/+/4085
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/build/bazel/go.MODULE.bazel b/build/bazel/go.MODULE.bazel
index d8836c4..1756ef7 100644
--- a/build/bazel/go.MODULE.bazel
+++ b/build/bazel/go.MODULE.bazel
@@ -56,6 +56,7 @@
     "com_github_miekg_dns",
     "com_github_mitchellh_go_wordwrap",
     "com_github_opencontainers_go_digest",
+    "com_github_opencontainers_image_spec",
     "com_github_opencontainers_runc",
     "com_github_packethost_packngo",
     "com_github_pkg_errors",