chore(deps): update dependency diffengine to 15.5.1 (#811)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

src/Directory.Packages.props

@@ -14,7 +14,7 @@
     <PackageVersion Include="Citrus.Avalonia" Version="2.1.1" />
     <PackageVersion Include="MessageBox.Avalonia" Version="3.1.6" />
     <PackageVersion Include="coverlet.msbuild" Version="6.0.2" />
-    <PackageVersion Include="DiffEngine" Version="15.5.0" />
+    <PackageVersion Include="DiffEngine" Version="15.5.1" />
     <PackageVersion Include="FluentAssertions" Version="6.12.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.11.0" />
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.0.1" />