Openapi version 3.1.0 support

[lehmanju]

Hey, we use 3scale and would like to reference an OpenAPI version 3.1.0. Currently it fails with the following error:

spec.openapiRef.url: Invalid value: "https://raw.githubusercontent.com/maximhq/bifrost/refs/tags/transports/v1.4.12/docs/openapi/openapi.json": error unmarshaling JSON: failed to unmarshal property "components" (*openapi3.Components): failed to unmarshal property "schemas" (*openapi3.Schemas): failed to unmarshal property "properties" (*openapi3.Schemas): failed to unmarshal property "items" (*openapi3.SchemaRef): failed to unmarshal property "properties" (*openapi3.Schemas): failed to unmarshal property "exclusiveMinimum" (*bool): json: cannot unmarshal number into Go value of type bool