Upgrade from xUnit 2 to xUnit 3

Co-authored-by: bastianeicher <414366+bastianeicher@users.noreply.github.com>

Author: Copilot

src/UnitTests/UnitTests.csproj

@@ -2,11 +2,13 @@
 
   <!-- Project properties -->
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <RootNamespace>TypedRest</RootNamespace>
     <TargetFrameworks>net48;net10.0</TargetFrameworks>
     <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
     <IsPackable>False</IsPackable>
     <DeterministicSourcePaths>False</DeterministicSourcePaths>
+    <NoWarn>xUnit1051;CS1591</NoWarn>
   </PropertyGroup>
   <PropertyGroup Condition="$(TargetFramework)=='net8.0'">
     <Nullable>enable</Nullable>
@@ -28,7 +30,7 @@
     <PackageReference Include="RichardSzalay.MockHttp" Version="7.0.0" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="10.0.3" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
-    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.v3" Version="3.2.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
   </ItemGroup>