aliasRef duplicates types for optional properties

[Jan-Wilamowski-Clario]

This type definition which has two properties that only differ in whether they are optional:

type Color = string;

export interface MyObject {
    color: Color;
    color2?: Color;
}

creates the following schema (with aliasRef: true)

{
  "MyObject": {
    "type": "object",
    "properties": {
      "color": {
        "$ref": "#/components/schemas/Color"
      },
      "color2": {
        "$ref": "#/components/schemas/Color_1"
      }
    },
    "required": [
      "color"
    ]
  },
  "Color": {
    "type": "string"
  },
  "Color_1": {
    "type": "string"
  }
}

In more complex cases, Color_1 will simply "$ref": "Color" which seems completely pointless. The intermediate types have names that are invalid model names in AWS API Gateway. Therefore, I cannot use aliasRef and basically have no way to do type aliases because all definitions are duplicated with aliasRef: false:

{
  "MyObject": {
    "type": "object",
    "properties": {
      "color": {
        "type": "string"
      },
      "color2": {
        "type": "string"
      }
    },
    "required": [
      "color"
    ]
  }
}

Using the latest library version 0.65.1 with Node v18.20.4.