Ignore docker and podman auth info if deserialization failed

[termoshtt]

Problem

For example, $HOME/.docker/config.json on Windows runner of GitHub Actions is following:

{
    "auths": {
        "https://index.docker.io/v1/": {}
    },
    "credsStore": "wincred"
}

Current implementation of ocipkg will fail if this config.json exists with

Error: InvalidJson(Error("missing field `auth`", line: 3, column: 35))

https://github.com/rust-math/rust-mkl-container/actions/runs/3038006115/jobs/4891157780

How to fix

This PR simply ignores such config.json which cause deserialization error.