Missing DoNotInherit annotation

[ismaelhamed]

Is there a reason why DoNotInherit is missing from the annotations? I can see it all over the place in the JVM. Would a PR be fine?

/// <summary>
/// <para>
/// Marks APIs that are designed under a closed-world assumption for and are NOT meant to be
/// extended by user-code. It is fine to extend these classes within Akka itself however.
/// </para>
/// <para>
/// This is most useful for binary compatibility purposes when a set of classes and interfaces
/// assume a "closed world" between them, and gain the ability to add methods to the interfaces
/// without breaking binary compatibility for users of this code. Specifically this assumption may be
/// understood intuitively: as all classes that implement this interface are in this compilation unit
/// artifact, it is impossible to obtain a "old" class with a "new" interface, as they are part of
/// the same dependency.
/// </para>
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface)]
public sealed class DoNotInheritAttribute: Attribute
{
}

[Aaronontheweb]

Yep, a PR would be fine.