Doesn't allow contentEncoding or contentMediaType properties on type:string in OAS 3.1

[BryanCrotazGivEnergy]

PR for this:

#165

Docs:
https://spec.openapis.org/oas/v3.1.0.html#considerations-for-file-uploads

[Gi60s]

Spec 3.1 is not currently supported, although I am actively working on it. I've looked at your PR and although I'm grateful for your desire to improve the library, because it doesn't support 3.1 I feel like this PR is more of a hack than an actual solution.

I'm sorry, because I'm sure that isn't the answer you're looking for.

Are you looking just for OpenAPI spec 3.1 validation or is there more that you want? I might be about a month out for an bare bone release that could support 3.1.