New templates have unnecessary using statement for OpenApi

[timheuer]

Describe the bug

With the change and merge of Program/Startup content for minimal hosting API support, an additional using that still exists is no longer needed due to the use of the new C# language feature and new() instead of using new OpenApiInfo() in the project file. This triggers code fixes to show that this using is not needed.

Generally we shouldn't emit code that our tools immediately flag as not needed.

To Reproduce

From VS:
File...New Project...Web API (C#)
Open Program.cs
OBSERVE: Roslyn grays out and lightbulbs the using Microsoft.OpenApi.Models

Further technical details

6.0.100-rc.1.21426.23
VS 2022 Int.Preview 4 (should repro on any VS2022 w/net6 sdk)

[Pilchie]

Tagging @DamianEdwards

[DamianEdwards]

Good catch.
@Pilchie OK to target rc.2 for a fix?

[Pilchie]

Yes, but the PR needs to either be re-targeted, or use the bot to trigger a backport PR.

[DamianEdwards]

OK I'll attempt to drive this in.