refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -18,7 +18,7 @@
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />
     <PackageVersion Include="Verify.ImageMagick" Version="3.7.0" />
     <PackageVersion Include="Verify.Nunit" Version="30.0.0" />
-    <PackageVersion Include="Microsoft.Sbom.Targets" Version="3.1.0" />
+    <PackageVersion Include="Microsoft.Sbom.Targets" Version="4.0.2" />
     <!-- explicit to avoid a cve -->
     <PackageVersion Include="System.Text.Json" Version="8.0.5" />
   </ItemGroup>