[BUG] aspnetcore server cannot be compiled with async and result Task option

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

I created an ASP .NET Core server from CLI with the additonal options operationResultTask=true and operationIsAsync=true. I used the public PetStore Open API spec in the newest version (currently 1.0.17). When I try to build the solution with VS 2022 (17.4.1) an error occurs:

openapi-generator version

6.2.1. I have not tested this in older versions.

OpenAPI declaration file content or url

https://raw.githubusercontent.com/swagger-api/swagger-petstore/master/src/main/resources/openapi.yaml

Generation Details

openapi-generator-cli generate -i petstore.yaml -g aspnetcore -o PetStore.Web --package-name PetStore.Web --additional-properties=operationResultTask=true,operationIsAsync=true

Steps to reproduce

1. Open the solution in VS 2022
2. Rebuild

Related issues/PRs

Dont know any.

Suggest a fix

Original code:

return Task.FromResult<IActionResult>(new ObjectResult(example));

Possible fix:

return new ObjectResult(example);

Reproduce the CLI generation using the PetStore OpenAPI URL and the stated operationResultTask=true,operationIsAsync=true options. Inspect the generated src/PetStore.Web/Controllers/PetApi.cs around line 60, then rebuild in Visual Studio; done means the generated ASP.NET Core solution compiles without CS4016.