deps: Bump Microsoft.NET.Test.Sdk from 18.3.0 to 18.4.0 (#60)

Author: dependabot[bot]

QsNet.Tests/QsNet.Tests.csproj

@@ -7,7 +7,7 @@
     <ItemGroup>
         <PackageReference Include="FluentAssertions" Version="8.9.0"/>
         <PackageReference Include="JetBrains.Annotations" Version="2025.2.4"/>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0"/>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.4.0"/>
         <PackageReference Include="xunit" Version="2.9.3"/>
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
             <PrivateAssets>all</PrivateAssets>