refs and cleanup

Author: SimonCropp

src/DiffEngine/DiffEngine.csproj

@@ -12,6 +12,7 @@
     <Using Include="System.Net.Sockets" />
     <Using Include="EmptyFiles" />
     <Using Include="System.ReadOnlySpan&lt;System.Char&gt;" Alias="CharSpan" />
+    <PackageReference Include="Microsoft.Sbom.Targets" PrivateAssets="all" />
     <PackageReference Include="System.Runtime.InteropServices.RuntimeInformation"
                       Condition="'$(TargetFramework)' == 'net462' OR '$(TargetFramework)' == 'net472'" />
     <PackageReference Include="Caseless.Fody" PrivateAssets="All" />

src/Directory.Packages.props

@@ -9,6 +9,7 @@
     <PackageVersion Include="EmptyFiles" Version="8.9.1" />
     <PackageVersion Include="Fody" Version="6.9.2" />
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.2" />
+    <PackageVersion Include="Microsoft.Sbom.Targets" Version="3.1.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageVersion Include="Polyfill" Version="7.30.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.152" />

src/VersionTests/VersionTests.csproj

@@ -1,8 +1,8 @@
 
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT'">net472;net48;net9.0</TargetFrameworks>
-    <TargetFrameworks>$(TargetFrameworks);net6.0;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT'">net48;net9.0</TargetFrameworks>
+    <TargetFrameworks>$(TargetFrameworks);net8.0;net9.0</TargetFrameworks>
     <GenerateAssemblyInfo>true</GenerateAssemblyInfo>
     <NoWarn>$(NoWarn);SYSLIB0012</NoWarn>
   </PropertyGroup>