remove isAnyTypeSchema in default codegen (#17663)

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -8202,51 +8202,6 @@ public class DefaultCodegen implements CodegenConfig {
         }
     }
 
-    /**
-     * This method has been kept to keep the introduction of ModelUtils.isAnyType as a non-breaking change
-     * this way, existing forks of our generator can continue to use this method
-     * TODO in 6.0.0 replace this method with ModelUtils.isAnyType
-     * Return true if the schema value can be any type, i.e. it can be
-     * the null value, integer, number, string, object or array.
-     * One use case is when the "type" attribute in the OAS schema is unspecified.
-     *
-     * Examples:
-     *
-     *     arbitraryTypeValue:
-     *       description: This is an arbitrary type schema.
-     *         It is not a free-form object.
-     *         The value can be any type except the 'null' value.
-     *     arbitraryTypeNullableValue:
-     *       description: This is an arbitrary type schema.
-     *         It is not a free-form object.
-     *         The value can be any type, including the 'null' value.
-     *       nullable: true
-     *
-     * @param schema the OAS schema.
-     * @return true if the schema value can be an arbitrary type.
-     */
-    public boolean isAnyTypeSchema(Schema schema) {
-        if (schema == null) {
-            once(LOGGER).error("Schema cannot be null in isAnyTypeSchema check");
-            return false;
-        }
-
-        if (ModelUtils.isFreeFormObject(schema)) {
-            // make sure it's not free form object
-            return false;
-        }
-
-        if (schema.getClass().equals(Schema.class) && schema.get$ref() == null && schema.getType() == null &&
-                (schema.getProperties() == null || schema.getProperties().isEmpty()) &&
-                schema.getAdditionalProperties() == null && schema.getNot() == null &&
-                schema.getEnum() == null) {
-            return true;
-            // If and when type arrays are supported in a future OAS specification,
-            // we could return true if the type array includes all possible JSON schema types.
-        }
-        return false;
-    }
-
     /**
      * Check if the given MIME is a JSON MIME.
      * JSON MIME examples: