feat(api): add conformance tests to github workflow

[gphorvath]

User Story

As an api
I want to always pass conformance tests
So that I can guarantee my behavior matches the OpenAI spec.

Acceptance Criteria

Given an API router
When an OpenAI SDK is used to access
Then I return the expected result

Describe alternatives you've considered

Additional context

This will require a project variable for the OPENAI_API_KEY with sufficient funding to run routinely.

We may need to precisely determine when to run these tests as they will be expensive due to larger runners and OpenAI API costs.