Deploy clerk_backend_api package

[slightfoot]

We believe it to be desirable for developers building building backend APIs in Dart to be able to simply and easily integrate Clerk's authentication system. This will require the Backend API surface to be deployed as a package on pub.dev.

OpenAPI Spec

• https://github.com/clerk/openapi-specs
• https://github.com/clerk/openapi-specs/blob/main/bapi/2024-10-01.yml

References

• https://clerk.com/docs/reference/backend-api
• https://clerk.com/docs/reference/backend-api/tag/Users#operation/GetOAuthAccessToken
• https://pub.dev/packages/openapi_generator
• https://pub.dev/packages/openapi_generator_cli
• https://pub.dev/packages/openapi_spec