[Refactor] Use multirun instead of bazel query to push/load all images

[dayeol]

Credit: thanks @rdzhou for bringing this up.

Maybe use multirun to create a "push_all" target instead of bazel query 'kind("oci_push", "//...")' | xargs -n1 bazel run, same for oci_load

I would create multirun rules push_all_images and load_all_images.