Bump DiffEngine from 12.0.0 to 12.1.0 (#712)

Bumps [DiffEngine](https://github.com/VerifyTests/DiffEngine) from 12.0.0 to 12.1.0.
- [Release notes](https://github.com/VerifyTests/DiffEngine/releases)
- [Commits](VerifyTests/DiffEngine@12.0.0...12.1.0)

---
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/ApprovalTests/ApprovalTests.csproj

@@ -11,7 +11,7 @@
     <Using Remove="System.Net.Http" />
     <PackageReference Include="Polyfill" Version="1.26.0" PrivateAssets="all" />
     <Compile Include="..\ApprovalUtilities\InternalsVisibleTo.cs" Link="InternalsVisibleTo.cs" />
-    <PackageReference Include="DiffEngine" Version="12.0.0" />
+    <PackageReference Include="DiffEngine" Version="12.1.0" />
     <PackageReference Include="EmptyFiles" Version="4.4.0" PrivateAssets="None" />
     <PackageReference Include="Fody" Version="6.8.0" PrivateAssets="all" />
     <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />