Enabling C# 9 in Xamarin & .NET Standard Projects

Whoa! .NET 5 is out and C# 9 is out! This means you are ready to use records, new pattern matching, and more! But wait a second... your apps haven't been upgraded to .NET 5 yet or are a project type that don't support .NET so you don't have access to the new C# 9 features :( Or do you!?!?!?!