[BUG] CodegenConfigurator crashing when allOf overridden

When trying to override a basic type alias with a default I get a stacktrace failure and com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'openapi': was expecting ('true', 'false' or 'null') and SwaggerCompatConverter - failed to read resource listing.

The guilty part of the spec looks something like (obviously simplified):

SomeThing:
  properties:
    duration:
      description: "The duration of SomeThing"
      default: 0
      allOf:
        - $ref: 'Duration'
Duration:
  type: integer
  description: Duration in seconds

Alternative forms fail the same way:

SomeThing:
  properties:
    duration:
      allOf:
        - $ref: 'Duration'
        - description: "The duration of SomeThing"
          default: 0
 
Duration:
  type: integer
  description: Duration in seconds

openapi-generator version

master, I think its a regression as I was using an older version of master /wo the issue

Command line used for generation

Occurs when I just validate. Also when generating rust /w reqwest but the bug hits way before any codegen happens

Steps to reproduce

Validate a spec that sets a default for an inherited schema object. Deleting the default allows it to validate.

Start with the CodegenConfigurator validation path and the SwaggerCompatConverter failure described in the report. Reproduce it with the minimal YAML containing Duration, allOf, and default, then compare validation with and without the default; done means the spec validates without the Jackson parse failure.