Bump NUnit3TestAdapter to 6.1.0

Update the NUnit3TestAdapter package reference in the test project from 5.2.0 to 6.1.0 to pick up bug fixes and compatibility improvements with the current test SDK.

Author: EdiWang

src/Edi.Captcha.Tests/Edi.Captcha.Tests.csproj

@@ -6,7 +6,7 @@
   <ItemGroup>
     <PackageReference Include="NUnit" Version="4.4.0" />
     <PackageReference Include="Moq" Version="4.20.72" />
-    <PackageReference Include="NUnit3TestAdapter" Version="5.2.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="6.1.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
   </ItemGroup>
   <ItemGroup>