Accordinf to https://spec.openapis.org/oas/latest.html#fixed-fields-6

Path item Object should support $ref as in the snippet below

paths:
    /orders:
         $ref: paths/orders.yaml

it looks not supported in the meta schema
https://github.com/OAI/OpenAPI-Specification/blob/main/schemas/v3.1/schema.yaml#L211

to me the line 209 is wrong

      '^/':
        $ref: '#/$defs/path-item'

but should be

      '^/':
        $ref: '#/$defs/path-item-or-reference:'

this has been found here : daveshanley/vacuum#422