Added support for application/yaml response payloads.

[dblock]

Description

On top of #360, Added application/yaml support and responses to cat APIs. This one requires deserializing the response body into an object to validate.

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[github-actions]

Changes Analysis

Commit SHA: 2128acc
Comparing To SHA: bb63d76

API Changes

Summary

└─┬Paths
  ├─┬/_cat/health
  │ └─┬GET
  │   └─┬Responses
  │     └─┬200
  │       └──[➕] content (23178:11)
  ├─┬/_cat/indices/{index}
  │ └─┬GET
  │   └─┬Responses
  │     └─┬200
  │       └──[➕] content (23199:11)
  └─┬/_cat/indices
    └─┬GET
      └─┬Responses
        └─┬200
          └──[➕] content (23199:11)

Document Element	Total Changes	Breaking Changes
paths	3	0

• Total Changes: 3
• Additions: 3

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/9716543764/artifacts/1649566586

API Coverage

	Before	After	Δ
Covered (%)	483 (47.31 %)	483 (47.31 %)	0 (0 %)
Uncovered (%)	538 (52.69 %)	538 (52.69 %)	0 (0 %)
Unknown	24	24	0

[nhtruong]

probably scope creeping but nullable is not a proper JSON schema keyword. Even if it was, this is redundant because nullable string already encapsulates non-nullable string.

In this case and a few below, we can repalce anyOf: ... with type: [string, null] according to this

[dblock]

I tried this but it failed with some other error. Care to open an issue with some details to replace?

The merge-base changed after approval.

[nhtruong]

This is stuck at "Checking for ability to merge automatically…"