The package validation reports LA0006 error, although it seems that it shouldn't

When you introduce a new **stable** API which is available on net6+ and is not on net62 the build pipeline fails with the `LA0006` error. For example, we introduced such an API in the following PR https://github.com/dotnet/extensions/pull/5670, and that caused the build pipeline to fail https://github.com/dotnet/extensions/runs/33204090775. The `LA0006` error stated

```output
Published symbol 'override System.Net.Http.HttpResponseMessage Microsoft.Extensions.Http.Resilience.ResilienceHandler.Send(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken);' cannot be deleted to maintain compatibility
```

We discussed the error in this thread https://github.com/dotnet/extensions/pull/5670#discussion_r1850640267, and agreed that the error, probably, shouldn't be reported in such a case.

We need to investigate whether the error was triggered correctly or not? If not, then we'll need to fix the analyzer.