properly tag nunit4 in NUnit4 Constrains nuget spec

Author: bodewig

RELEASE_NOTES.md

@@ -2,6 +2,9 @@
 
 ## XMLUnit.NET 2.11.1 - /Not Released, yet/
 
+* the NUnit 4.x constraints package tags nunit3 rather than nunit4.
+  PR [#43](https://github.com/xmlunit/xmlunit.net/issues/43).
+
 ## XMLUnit.NET 2.11.0 - /Released 2025-03-28/
 
 * introduced a new constraints library for NUnit 4.x as the NUnit 3.x

src/main/net-constraints-nunit4/XMLUnit.NUnit4.Constraints.nuspec

@@ -21,7 +21,7 @@
       <frameworkAssembly assemblyName="System.Xml" />
       <frameworkAssembly assemblyName="System.Xml.Linq" />
     </frameworkAssemblies>
-    <tags>xmlunit xml unit-testing test xmldiff nunit nunit3</tags>
+    <tags>xmlunit xml unit-testing test xmldiff nunit nunit4</tags>
   </metadata>
   <files>
     <file src="..\..\..\build/NetFramework/bin/Release/xmlunit-nunit4-constraints.dll" target="lib\net462"/>