Make ObjectFactory<T> covariant

[alrz]

Closes #101829

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[lilinus]

I think you need to update src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/ref/Microsoft.Extensions.DependencyInjection.Abstractions.cs too?

[alrz]

I think you need to update src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/ref/Microsoft.Extensions.DependencyInjection.Abstractions.cs too?

Yes, thanks! I did it manually for this change though, is there a tool to regenerate refs?

[huoyaoyuan]

is there a tool to regenerate refs?

See https://github.com/dotnet/runtime/blob/main/docs/coding-guidelines/updating-ref-source.md

[huoyaoyuan]

The API proposal hasn't been reviewed yet. Since it's so trivial, it's a bit eager to open this PR.

[alrz]

The API proposal hasn't been reviewed yet.

Right, I believe this was missed the first time it was introduced, I don't mind this being left open until then though.