refs or cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -4,9 +4,9 @@
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0" />
+    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
-    <PackageVersion Include="Polyfill" Version="9.17.0" />
+    <PackageVersion Include="Polyfill" Version="9.18.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.172" />
     <PackageVersion Include="Verify" Version="31.13.2" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />
@@ -19,7 +19,7 @@
     <PackageVersion Include="System.Text.Json" Version="10.0.3" />
     <PackageVersion Include="Microsoft.Extensions.Caching.Memory" Version="10.0.3" />
     <PackageVersion Include="Argon" Version="0.33.5" />
-    <PackageVersion Include="DiffEngine" Version="18.4.2" />
+    <PackageVersion Include="DiffEngine" Version="19.0.0" />
     <PackageVersion Include="EmptyFiles" Version="8.17.2" />
     <PackageVersion Include="SimpleInfoName" Version="3.2.0" />
   </ItemGroup>