I want to create a static abstract member in an interface within a .NET Standard 2.1 project. Everything I’ve read says that this just requires C#11. I set the LangVersion tag in the project file but I get the error:

CS8919 Target runtime doesn’t support static abstract members in interfaces.

I know there are some features that require additional steps (for example, see this question). Is there a package I can add or anything else I can do?

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.1</TargetFramework>
    <LangVersion>11.0</LangVersion>
    <Nullable>enable</Nullable>
  </PropertyGroup>

</Project>

public interface ITest
{
    static abstract int GetInt();
}