Spectral schema/propertyNames rule does not flag invalid response codes for PUT

[Marton-J]

Describe the bug
A Spectral rule using the schema/propertyNames approach does not flag invalid response codes for PUT operations in OpenAPI 3.1.1, even when the test data clearly violates the rule.

To Reproduce

.spectral.yaml:

put-must-only-return-200-or-201:
  description: "PUT ska endast returnera 200 OK eller 201 Created."
  message: "PUT får endast returnera 200 eller 201."
  severity: error
  given: $.paths[*].put.responses
  then:
    function: schema
    functionOptions:
      schema:
        type: object
        propertyNames:
          pattern: "^(200|201)$"

[test.json]:

"/dokumentarkivinfo/api/v1/dokument/{dokumentId}": {
  "put": {
    "responses": {
      "204": {
        "description": "No Content"
      }
    }
  }
}

Expected behavior
Spectral should flag the PUT operation as invalid because it returns 204 instead of 200 or 201.

Environment (remove any that are not applicable):

• spectral 6.15.0
• Windows 11