Using openapi3::OpenApi with schemars alpha version

Hello!

My goal is to produce an OpenApi spec using schemars.

I have a code:
```rust
let my_schemas: okapi::Map:: = ... // generated by schemars ^0.8

OpenApi {
openapi: "3.0.0".to_string(),
info: okapi::openapi3::Info {
title: "My API".to_string(),
version: "1.0.0".to_string(),
..Default::default()
},
components: Some(okapi::openapi3::Components {
schemas: my_schemas,
..Default::default()
}),
..Default::default()
}
```
Which works perfectly with `schemars ^0.8`.

However, I would like to use `schemars 1.0.0-alpha.17` as it has [better](https://github.com/GREsau/schemars/issues/165) enum support and seems it has more useful features.

There is a problem. Now `my_schemas` type would be `Schema(Value)` from alpha version which is not compatible with `OpenApi::components::schemas` type `Map` as `schemars ^0.8` generate except manually implementing that transformation which can be quirky. Another option I see is to generate pure json instead of using openapiv3::OpenApi

Could you please suggest a pretty solution for this issue?

cc @GREsau