Regression from 6.11.1->6.13.1 parsing OpenAPI specs with an operation using $ref

[robjtede]

Describe the bug

For an OpenAPI v3.1 spec including this, for example:

paths:
  /token:
    post:
      $ref: '_api-login.yml#/operations/login'

We now receive this error:

 nn:10  error  oas3-schema  "post" property must not have unevaluated properties.  paths./token.post

This seemed to work fine in Spectral v6.11.1.

To Reproduce

1. Given the OpenAPI document above.
2. Run this CLI command 'spectral lint'
3. See error shown.
4. See error is not shown when using v6.11.1.

Expected behavior Spec should be parsed and reference resolved, as it is in other contexts.

Environment (remove any that are not applicable):

• Library version: v6.13.1
• OS: Ubuntu
• Browser: N/A

Additional context I understand that it's possible, via a strict reading of OAS v3.1, that this is not supposed to be allowed and supporting it previously was a bug. However, it's worth it to me to check the team's stance on that, given that I'd like it to be supported (and actually might be worth a contribution to the spec itself).