Upgrade Jint from 4.8.0 to 4.15.3

Package provenance verified after restore: source is
https://api.nuget.org/v3/index.json and the nuspec repository commit is
a304aa5dacd340e2a5ff51e1ea0c465e38e50aa8, the v4.15.3 tag. Acornima moves
to 1.6.2 transitively; ParseErrorException, ScriptPreparationException and
JintException, which JintScriptEngine.MapException switches on, all still
exist, and so do Engine.Constraints.Reset, Options.Constraints.PromiseTimeout,
AllowClrWrite, EvaluateAsync(in Prepared<Script>, CancellationToken),
ObjectWrapper.Create and the ObjectInstance virtuals the ContentWrapper
family overrides.

No source change is needed for the upgrade itself: the whole backend
solution builds warning-clean and all 156 tests in Operations/Scripting,
including the behaviour pins added in the previous commit, pass unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016uV6H9cTntzsoKiaJRBn4f

backend/src/Squidex.Domain.Apps.Core.Operations/Squidex.Domain.Apps.Core.Operations.csproj

@@ -20,7 +20,7 @@
   <ItemGroup>
     <PackageReference Include="Fluid.Core" Version="2.31.0" />
     <PackageReference Include="GeoJSON.Net" Version="1.4.1" />
-    <PackageReference Include="Jint" Version="4.8.0" />
+    <PackageReference Include="Jint" Version="4.15.3" />
     <PackageReference Include="Meziantou.Analyzer" Version="3.0.50">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>