chore(deps): update dependency nunit to 4.3.1

Author: renovate[bot]

Diff for: Test/Test.csproj

@@ -19,7 +19,7 @@ SPDX-License-Identifier: MIT
     </PackageReference>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageReference Include="Mono.Posix" Version="7.1.0-final.1.21458.1" />
-    <PackageReference Include="NUnit" Version="4.2.2" />
+    <PackageReference Include="NUnit" Version="4.3.1" />
     <PackageReference Include="NUnit.Analyzers" Version="4.4.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />