[BUG] [swift5] for nullable and required field default nil is not generated

[mikehouse]

Bug Report Checklist

• [ x] Have you provided a full/minimal spec to reproduce the issue?
• [ ] Have you validated the input using an OpenAPI validator (example)?
• [ x] Have you tested with the latest master to confirm the issue still exists?
• [x ] Have you searched for related issues/PRs?
• [ x] What's the actual output vs expected output?
• [ ] [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When properly is nullable in Swift we'd like to get a setup for default value to nil to it, like this below

public struct MyStruct: Codable, Hashable {

    public var value: Decimal?

    public init(value: Decimal? = nil) {
        self.value = value
    }
}

But when a field in json scheme set as nullable and required then I get such result

public struct MyStruct: Codable, Hashable {

    public var value: Decimal?

    public init(value: Decimal?) {
        self.value = value
    }
}

openapi-generator version

openapi-generator-cli-7.9.0-20241004.072436-107.jar

OpenAPI declaration file content or url

      "MyStruct": {
        "properties": {
          "value": {
            "anyOf": [
              { "type": "string", "format": "decimal" },
              { "type": "null" }
            ],
            "title": "Value"
          },
        },
        "type": "object",
        "required": ["value"],
        "title": "MyStruct"
      },

Generation Details

Steps to reproduce

Related issues/PRs

Suggest a fix

I fixed it by custom template (just updated existed modelObject.mustache template), but it would be nice to have it from out the box. Thank you.