Possibly incorrect "Code Correctness: Missing [Serializable] Attribute" finding on RegEx class.

This finding is preventing us from using the GeneratedRegex attribute to generate optimal regex code.

I've been discussing this one with Microsoft and here is their response:

"The base Regex still inherits ISerializable because removing it would be a binary breaking change, but if you try to serialize/deserialize a Regex, you'll get a PlatformNotSupportedException. And Regex itself is not marked [Serializable].

We will not be making Regex or source-generated derivations [Serializable]."