Fix trim annotations on generated validation code

[sbomer]

The generated code currently produces a trim warning at k.ContainingType.GetProperty:

ValidatableInfoResolver.g.cs(263,32): error IL2075: 'this' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicProperties' in call to 'System.Type.GetProperty(String)'. The return value of method 'Microsoft.AspNetCore.Http.Validation.Generated.ValidationAttributeCache.CacheKey.ContainingType.get' does not have matching annotations. The source value must declare at least the same requirements as those declared on the target location it is assigned to.

[BrennanConroy]

Seems like we should have a linker/aot verification test.
e.g. https://github.com/dotnet/aspnetcore/blob/main/src/SignalR/server/SignalR/test/Microsoft.AspNetCore.SignalR.Tests/NativeAotTests.cs

[captainsafia]

I opened #61927 to update the snapshot tests since the original branch didn't let me push.

I still kept your commit @sbomer so you'll get credit for the change.