我会创建一个新的非泛型接口并将其用作签名。

// Empty base interface used as a signature
public interface IReadableEntity {}

public interface IReadableEntity<T> : IReadableEntity
{
  void DoSomething(T value);
}

public class SampleReadableEntity : IReadableEntity<int>
{
  public void DoSomething(int value);
}

var services = new ServiceCollection()
.AddSingleton<SampleReadableEntity >()
.AddSingleton<IReadableEntity<int>>(provider => provider.GetRequiredService<SampleReadableEntity >())
.AddSingleton<IReadableEntity>(provider => provider.GetRequiredService<SampleReadableEntity >())
.BuildServiceProvider();

var allReadableEntities = services.GetServices<IReadableEntity>();
var allIntReadableEntities = service.GetServices<IReadableEntity<int>>();
var sampleReadableEntity = services.GetService<SampleReadableEntity>();