Make ObjectFactory<T> covariant (dotnet#102553)

Author: alrz

src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/ref/Microsoft.Extensions.DependencyInjection.Abstractions.cs

@@ -73,7 +73,7 @@ public static partial class KeyedService
         public static object AnyKey { get { throw null; } }
     }
     public delegate object ObjectFactory(System.IServiceProvider serviceProvider, object?[]? arguments);
-    public delegate T ObjectFactory<T>(System.IServiceProvider serviceProvider, object?[]? arguments);
+    public delegate T ObjectFactory<out T>(System.IServiceProvider serviceProvider, object?[]? arguments);
     public partial class ServiceCollection : Microsoft.Extensions.DependencyInjection.IServiceCollection, System.Collections.Generic.ICollection<Microsoft.Extensions.DependencyInjection.ServiceDescriptor>, System.Collections.Generic.IEnumerable<Microsoft.Extensions.DependencyInjection.ServiceDescriptor>, System.Collections.Generic.IList<Microsoft.Extensions.DependencyInjection.ServiceDescriptor>, System.Collections.IEnumerable
     {
         public ServiceCollection() { }

src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/src/ObjectFactoryT.cs

@@ -12,5 +12,5 @@ namespace Microsoft.Extensions.DependencyInjection
     /// <param name="serviceProvider">The <see cref="IServiceProvider"/> to get service arguments from.</param>
     /// <param name="arguments">Additional constructor arguments.</param>
     /// <returns>An instance of type <typeparamref name="T" />.</returns>
-    public delegate T ObjectFactory<T>(IServiceProvider serviceProvider, object?[]? arguments);
+    public delegate T ObjectFactory<out T>(IServiceProvider serviceProvider, object?[]? arguments);
 }