Update api parity docs and update graphQL cookbook

[jeremybumsted]

We have the ability to query detailed retry info for jobs on a given build with only the GraphQL api, so this will update the api differences page, as well as add a query that shows how to do this as an example.

[buildkite-docs-bot]

Preview URL: https://2243--bk-docs-preview.netlify.app

[mbelton-buildkite]

A couple of tweaks, then it looks good 😊

[jeremybumsted]

Amazing, thanks @mbelton-buildkite :)

[mbelton-buildkite]

^ I merged in main to pick up a fix for the failing build.

[ozdenyilmaz]

This PR is no longer needed. Both changes have already been applied to the current codebase:

Job retry cookbook entry — The GraphQL cookbook now has a "Get retry information for a job" section in pages/apis/graphql/cookbooks/jobs.md (line 195), with an even more detailed query that includes retrySource, retryType, and retriedBy.
API differences page — Line 17 already lists "Retry data for jobs" under REST-only features, and the GraphQL-only section doesn't need an entry since retry info is now documented in the GraphQL cookbooks. The feature parity gap the PR was documenting has been addressed.

The PR can be safely closed.