Update dependency nunit to v4

Author: renovate[bot]

mama/dotnet/src/nunittest/mamadotnetunittests.csproj

@@ -14,7 +14,7 @@
     </PropertyGroup>
     <ItemGroup>
         <PackageReference Include="NUnitLite" Version="3.14.0" />
-        <PackageReference Include="nunit" Version="3.14.0" />
+        <PackageReference Include="nunit" Version="4.3.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     </ItemGroup>

mamda/dotnet/src/NUnittest/mamdadotnetunittests.csproj

@@ -11,7 +11,7 @@
         <Company>OpenMAMA.org</Company>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.14.0" />
+        <PackageReference Include="nunit" Version="4.3.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     </ItemGroup>