Generate OAS for APIs that have stack availability

[lcawl]

🚀 Feature Proposal

In addition to the https://github.com/elastic/elasticsearch-specification/blob/main/output/openapi/elasticsearch-serverless-openapi.json output file, we need one that reflects the APIs that have availability set to stack.

In the past, that larger OAS file was generated and stored in a separate internal repo, but I don't know how up-to-date that one is.

Motivation

We'll need the full set of public APIs in OAS format in order to generate API documentation.

Example

N/A

[lcawl]

Fixed by #2608 ?

[l-trotta]

yes!