chore(deps): update dependency diffengine to v15.4.0 (#928)

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

src/Akavache.Tests/Akavache.Tests.csproj

@@ -23,7 +23,7 @@
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <PackageReference Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.8" />
     <PackageReference Include="FluentAssertions" Version="6.12.0" />
-    <PackageReference Include="DiffEngine" Version="15.3.0" />
+    <PackageReference Include="DiffEngine" Version="15.4.0" />
     <PackageReference Include="PublicApiGenerator" Version="11.1.0" />
     <PackageReference Include="Verify.Xunit" Version="24.1.0" />
     <PackageReference Include="coverlet.msbuild" Version="6.0.2">