Upgrade to xUnit v3 as requested

- Updated xunit package from v2.9.2 to xunit.v3 v3.1.0
- Updated xunit.runner.visualstudio from v2.8.2 to v3.1.5
- Updated Microsoft.NET.Test.Sdk to v17.11.1
- Added OutputType=Exe property for xUnit v3 compatibility
- Updated Verify.Xunit to Verify.XunitV3 v31.0.2 for Bootstrap tests
- Updated using statements to use VerifyXunit namespace
- All tests passing with xUnit v3

Co-authored-by: JohnCampionJr <1094820+JohnCampionJr@users.noreply.github.com>

Author: Copilot

test/Directory.Build.props

@@ -4,12 +4,13 @@
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
     <TargetFramework>net8.0</TargetFramework>
+    <OutputType>Exe</OutputType>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="xunit" Version="2.9.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="xunit.v3" Version="3.1.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>

test/FluentEmail.Bootstrap.Tests/BootstrapTests.cs

@@ -9,8 +9,8 @@
 using Microsoft.Extensions.FileProviders;
 using Microsoft.Extensions.Options;
 using Xunit;
-using VerifyXunit;
 using VerifyTests;
+using VerifyXunit;
 
 namespace FluentEmail.Bootstrap.Tests;
 

test/FluentEmail.Bootstrap.Tests/FluentEmail.Bootstrap.Tests.csproj

@@ -14,8 +14,8 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.FileProviders.Embedded" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Physical" Version="8.0.0" />
-    <PackageReference Update="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="Verify.Xunit" Version="28.0.0" />
+    <PackageReference Update="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="Verify.XunitV3" Version="31.0.2" />
   </ItemGroup>
 
 </Project>