chore(openapi): migrate to openapi spec version 3.1.0

[zevisert]

Migrates the open inference protocol specification to openapi version 3.1.0.

I followed the upgrade guide posted by openapi: https://www.openapis.org/blog/2021/02/16/migrating-from-openapi-3-0-to-3-1-0

Closes #14

[zevisert]

I removed the examples that were provided in #/components/schemas/inference_request, as they were misleading. The shape provided in each example did not match the data provided.

• Example 1/input0 had shape [2, 2] but provided data [1, 2, 3, 4] of shape [4]
• Example 1/input1 had shape [3] but provided data [true] of shape [1]
• Example 2/output0 had shape [3, 2] but provided data [1, 1.1, 2, 2.1, 3, 3.1] of shape [6]