upgrade NUnit3TestAdapter 6.1.0

Author: ikpil

test/Box2D.NET.Test/Box2D.NET.Test.csproj

@@ -25,7 +25,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="NUnit3TestAdapter" Version="6.0.1" />
+    <PackageReference Include="NUnit3TestAdapter" Version="6.1.0" />
   </ItemGroup>
 
   <ItemGroup>