build(deps): bump DiffEngine from 6.5.5 to 6.5.6 in /src (#152)

Bumps [DiffEngine](https://github.com/VerifyTests/DiffEngine) from 6.5.5 to 6.5.6.
- [Release notes](https://github.com/VerifyTests/DiffEngine/releases)
- [Commits](https://github.com/VerifyTests/DiffEngine/commits)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/Directory.build.props

@@ -34,7 +34,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="DiffEngine" Version="6.5.5" />
+    <PackageReference Include="DiffEngine" Version="6.5.6" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">