build(deps): bump DiffEngine from 6.8.2 to 6.9.0 in /src (#175)

Bumps [DiffEngine](https://github.com/VerifyTests/DiffEngine) from 6.8.2 to 6.9.0.
- [Release notes](https://github.com/VerifyTests/DiffEngine/releases)
- [Commits](VerifyTests/DiffEngine@6.8.2...6.9.0)

---
updated-dependencies:
- dependency-name: DiffEngine
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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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="6.8.2" />
+    <PackageReference Include="DiffEngine" Version="6.9.0" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">