refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -39,6 +39,6 @@
     <PackageVersion Include="xunit.v3" Version="2.0.2" />
     <PackageVersion Include="xunit.v3.extensibility.core" Version="2.0.2" />
     <PackageVersion Include="YoloDev.Expecto.TestSdk" Version="0.15.3" />
-    <PackageVersion Include="Microsoft.Sbom.Targets" Version="3.1.0" />
+    <PackageVersion Include="Microsoft.Sbom.Targets" Version="4.0.2" />
   </ItemGroup>
 </Project>