Add a SHA256 SFV checksum file after dotnet publish

Hash.targets

<?xml version="1.0" encoding="utf-8"?>
<Project>
  <Target Name="PublishHash" AfterTargets="AfterPublish">
    <ItemGroup>
      <FilesToHash Include="$(PublishDir)**" Exclude="$(PublishDir)*.sha256;" />
    </ItemGroup>

    <GetFileHash Files="@(FilesToHash)" Algorithm="SHA256">
      <Output TaskParameter="Items" ItemName="Hashes" />
    </GetFileHash>

    <WriteLinesToFile File="$(PublishDir)$(AssemblyName).sha256" Lines="@(Hashes->'%(FileHash) %(Identity)'->Replace($(PublishDir), ''))" Overwrite="true"/>
  </Target>
</Project>