Added items to Schema equals and hashcode

Fixed a problem where `Schema` was not using the `items` property in the `equals()` or `hashcode()` method. This appears to have been missed when moving the `items` property off of the `ArraySchema` class and onto the `Schema` class.

Author: jeff-miller-cfa

modules/swagger-models/src/main/java/io/swagger/v3/oas/models/media/Schema.java

@@ -1965,7 +1965,8 @@ public boolean equals(java.lang.Object o) {
  Objects.equals(this.dependentSchemas, schema.dependentSchemas) &&
  Objects.equals(this.$comment, schema.$comment) &&
  Objects.equals(this.examples, schema.examples) &&
- Objects.equals(this.prefixItems, schema.prefixItems)
+ Objects.equals(this.prefixItems, schema.prefixItems) &&
+ Objects.equals(this.items, schema.items)
 
  ;
  }
@@ -1979,7 +1980,7 @@ public int hashCode() {
  discriminator, _enum, _default, patternProperties, $id, $anchor, $schema, types, allOf, anyOf, oneOf, _const,
  contentEncoding, contentMediaType, contentSchema, propertyNames, unevaluatedProperties, maxContains,
  minContains, additionalItems, unevaluatedItems, _if, _else, then, dependentRequired, dependentSchemas,
- $comment, examples, prefixItems);
+ $comment, examples, prefixItems, items);
  }
 
  public java.util.Map<String, Object> getExtensions() {