Proj0056: Enable nullability analysis for F#

F# 9.0 introduced support for nullable reference types to match C#’s null-safety checks for interoperability with C# code.

To enforce null-safety in F# projects, you should explicitly set the <Nullable> property to enable.

Non-compliant

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

  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
  </PropertyGroup>

</Project>

Or:

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

  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <Nullable>disable</Nullable>
  </PropertyGroup>

</Project>

Compliant

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

  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <Nullable>enable</Nullable>
  </PropertyGroup>

</Project>