Pr 2982 ci branch (#3046)
* Add json_schema alias for GrammarType
* Add tests for all aliases
* fix: various linter adjustments
* fix: end-of-file-fixer lint
* fix: add test snapshots and avoid docs change
* fix: another end-of-file-fixer lint
* feat: support json_schema grammar constraining and add tests
* fix: bump openapi doc with new grammar option
* fix: adjust test payload
* fix: bump test snaps
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Co-authored-by: Alex Weston <alexw@alkymi.io>
