Update dependency Microsoft.NET.Test.Sdk to v18 (#1619)

Co-authored-by: dependencyupdates[bot] <218638057+dependencyupdates[bot]@users.noreply.github.com>

Author: dependencyupdates[bot]

src/ServiceInsight.Tests/ServiceInsight.Tests.csproj

@@ -20,7 +20,7 @@
     <!-- ApprovalTests.Wpf 4.x doesn't support the .NET Framework -->
     <PackageReference Include="ApprovalTests.Wpf" Version="[3.0.18,4.0.0]" />
     <PackageReference Include="GitHubActionsTestLogger" Version="2.4.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.0" />
     <PackageReference Include="NSubstitute" Version="5.3.0" />
     <PackageReference Include="NUnit" Version="4.4.0" />
     <PackageReference Include="NUnit.Analyzers" Version="4.10.0" />