[Feature]: PHPDoc with union of constant strings could/should be considered an enum

[RobertMe]

Description

Hi,

I have some code like this:

/**
 * @var 'one'|'two'|'three'
 */
public string $prop;

In the OpenAPI JSON this however is rendered into:

"prop": {
  "oneOf": [
    {
      "type": "string"
    },
    {
      "type": "string"
    },
    {
      "type": "string"
    }
  ]
},

Which obviously is kinda wrong because of the oneOf which contains the same value ({"type": "string"}) multiple times.

Furthermore it would be nice if this union would automatically be converted into an enum, resulting in:

"prop": {
  "type": "string",
  "enum": [
    "one",
    "two",
    "three"
  ]
}

Additional context

No response

[Robert-Embloom]

In addition to this. When setting an enum as well (either using #[Property(enum: ['one', 'two', 'three']) or using Symfony-s Choice constraint) this "breaks" Swagger UI as well, as it just shows the oneOf and not the enum. When then removing this PHPDoc it does properly show the possible enum values. Which in turn also makes me wonder whether it would actually be valid to have a combination of enum and oneOf (as I can imagine that the enum cases all must be of the same type).