[Breaking Change] Cross-Version PR check reports false positive AddedRequiredProperty error

The BreakingChange CrossVersion PR check in [PR 23076](https://github.com/Azure/azure-rest-api-specs/pull/23076/checks?check_run_id=11994461656) reports an AddedRequiredProperty error for the new `chat_completions` property in the `Capabilities` schema:

The description of [AddedRequiredProperty](https://github.com/Azure/openapi-diff/blob/master/docs/rules/1034.md) (which is linked from the report in the PR) says:

> Description: Checks whether a new required property has added from the previous specification.
>
> Cause: This is considered a breaking change. This change requires new api-version.

But this change _is_ in a new api-version. Further, the `Capabilities` schema is only used in response bodies, so adding a required property is not "breaking".