Migrate all projects and tests to .NET 11.0

Upgraded the target framework for all main, test, and provider projects from .NET 10.0 (net10.0) to .NET 11.0 (net11.0). Updated all major NuGet dependencies to their .NET 11-compatible versions, including Microsoft.AspNetCore.*, Microsoft.EntityFrameworkCore.*, Microsoft.Extensions.*, Serilog, System.Text.Json, and Npgsql.EntityFrameworkCore.PostgreSQL (now 11.0.0-preview.1). Regenerated all project.assets.json, NuGet cache, and MSBuild files to reflect the new framework and package versions. Removed or updated incompatible dependencies and references. Set allWarningsAsErrors: true in NuGet spec files for stricter builds. No application logic changes were made; all updates are related to project configuration, dependency management, and build system modernization for .NET 11.0.

Jellyfin.Api/obj/Debug/net10.0/Jellyfin.Api.AssemblyInfo.cs

@@ -15,7 +15,7 @@ using System.Reflection;
 [assembly: System.Reflection.AssemblyCompanyAttribute("Jellyfin.Api")]
 [assembly: System.Reflection.AssemblyConfigurationAttribute("Debug")]
 [assembly: System.Reflection.AssemblyFileVersionAttribute("1.0.0.0")]
-[assembly: System.Reflection.AssemblyInformationalVersionAttribute("1.0.0+ae274053a886dcab4aa102adffb10460398730df")]
+[assembly: System.Reflection.AssemblyInformationalVersionAttribute("1.0.0+fd03e1f5645707581999115e9e2724708a49a331")]
 [assembly: System.Reflection.AssemblyProductAttribute("Jellyfin.Api")]
 [assembly: System.Reflection.AssemblyTitleAttribute("Jellyfin.Api")]
 [assembly: System.Reflection.AssemblyVersionAttribute("1.0.0.0")]

Jellyfin.Api/obj/Debug/net10.0/Jellyfin.Api.AssemblyInfoInputs.cache

@@ -1 +1 @@
-cd8b6e0608b5d156e56b48253eaad50ad4eecff7b7fe7e40b8e0f927e1b0f40e
+b941e6bcc4cd4683889265a26e9537848fc630341a3cd455562586b6cae3aedf