[BUG] [dart] Invalid code generated (validation_error_loc_inner.dart) (openapi 3.1.0)

[Gigahawk]

Bug Report Checklist

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

Description

Using the dart generator creates code that does not compile due to errors in validation_error_loc_inner.dart

...
class ValidationErrorLocInner {
  /// Returns a new [ValidationErrorLocInner] instance.
  ValidationErrorLocInner({
  });

  @override
  bool operator ==(Object other) => identical(this, other) || other is ValidationErrorLocInner &&

  @override
  int get hashCode =>
    // ignore: unnecessary_parenthesis
...

A screenshot to show highlighting of invalid syntax:

openapi-generator version

$ openapi-generator-cli version
7.6.0

OpenAPI declaration file content or url

https://gist.github.com/Gigahawk/a2e79529adb4206fd23c86e9c28a0380

Generation Details

Steps to reproduce

$ openapi-generator-cli generate -i openapi.json -g dart -o packages/openapi

Related issues/PRs

gibahjoe/openapi-generator-dart#135

Suggest a fix

[Gigahawk]

Duplicate of #13302