chore: bump Microsoft.NET.Test.Sdk to v18.x

Author: vbreuss

.idea/.idea.System.IO.Abstractions/.idea/copilot.data.migration.agent.xml

@@ -21,7 +21,7 @@
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.7" />
     <PackageVersion Include="coverlet.collector" Version="6.0.4" />
     <PackageVersion Include="GitHubActionsTestLogger" Version="2.4.1" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Moq" Version="4.20.72" />
     <PackageVersion Include="NUnit" Version="4.4.0" />
     <PackageVersion Include="NUnit.Analyzers" Version="4.11.2" />

.idea/.idea.System.IO.Abstractions/.idea/copilot.data.migration.ask.xml

@@ -9,6 +9,7 @@
         <NoWarn>$(NoWarn);S2699</NoWarn>
         <IsPackable>false</IsPackable>
         <IsTestable>true</IsTestable>
+        <SuppressTfmSupportBuildErrors>true</SuppressTfmSupportBuildErrors>
     </PropertyGroup>
 
     <ItemGroup>