3.1.0 spec procesing, nonexistant types added

[spacether]

When parsing this spec:

# OAS document that uses 3.1 features:
# 'null' type
# type array
openapi: 3.1.0
info:
  version: 1.0.0
  title: Example
  license:
    name: MIT
    identifier: MIT
servers:
  - url: http://api.example.xyz/v1
paths:
  /somePath:
    get:
      operationId: getSomePath
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema: {}
components:
  schemas:
    ArrayContainsValue:
      type: array
      contains:
        enum:
          - 1
    AnyTypeContainsValue:
      contains:
        enum:
          - 1
    AdditionalpropertiesBeingFalseDoesNotAllowOtherProperties:
      $schema: https://json-schema.org/draft/2020-12/schema
      properties:
        foo: {}
        bar: {}
      patternProperties:
        ^v: {}
      additionalProperties: false

1. The schema in ArrayContainsValue.contains is given the property types = LinkedHashSet("number")
   This is incorrect because we see from the schema above that the schema there only defines an enum value and that anytype (type unset/null) is the correct definition.
2. Type object is incorrectly set for AdditionalpropertiesBeingFalseDoesNotAllowOtherProperties

Can the parser be updated to show that the type for this use case is null?

This bug was hit on the additionalProperties test case AdditionalpropertiesBeingFalseDoesNotAllowOtherProperties when working on openapi-json-schema-tools/openapi-json-schema-generator#241