Update dependency Microsoft.NET.Test.Sdk to v18 (#16)

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

Author: dependencyupdates[bot]

src/NServiceBus.Envelope.CloudEvents.Tests/NServiceBus.Envelope.CloudEvents.Tests.csproj

@@ -16,7 +16,7 @@
 
   <ItemGroup>
     <PackageReference Include="GitHubActionsTestLogger" Version="3.0.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageReference Include="NUnit" Version="4.4.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
   </ItemGroup>