build(deps): bump DiffEngine from 6.1.4 to 6.4.6 (#2586)

Bumps [DiffEngine](https://github.com/VerifyTests/DiffEngine) from 6.1.4 to 6.4.6.
- [Release notes](https://github.com/VerifyTests/DiffEngine/releases)
- [Commits](https://github.com/VerifyTests/DiffEngine/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

src/Directory.build.props

@@ -50,7 +50,7 @@
     <PackageReference Include="FluentAssertions" Version="5.10.3" />
     <PackageReference Include="Microsoft.Reactive.Testing" Version="5.0.0" />
     <PackageReference Include="PublicApiGenerator" Version="10.2.0" />
-    <PackageReference Include="DiffEngine" Version="6.1.4" />
+    <PackageReference Include="DiffEngine" Version="6.4.6" />
     <PackageReference Include="coverlet.msbuild" Version="2.9.0" PrivateAssets="All" />
   </ItemGroup>