Update dependency Microsoft.Testing.Extensions.CodeCoverage to v18

Author: renovate[bot]

Directory.Packages.props

@@ -26,7 +26,7 @@
         <PackageVersion Include="JetBrains.ReSharper.GlobalTools" Version="2025.3.1" />
         <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.0.0" />
         <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Features" Version="5.0.0" />
-        <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="17.14.2" />
+        <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.3.1" />
         <PackageVersion Include="Microsoft.Testing.Extensions.TrxReport" Version="1.8.5" />
         <PackageVersion Include="GitVersion.Tool" Version="6.5.1" />
         <PackageVersion Include="Nuke.Common" Version="9.0.4" />