Bump NUnit from 4.2.2 to 4.3.1

Bumps [NUnit](https://github.com/nunit/nunit) from 4.2.2 to 4.3.1.
- [Release notes](https://github.com/nunit/nunit/releases)
- [Changelog](https://github.com/nunit/nunit/blob/main/CHANGES.md)
- [Commits](nunit/nunit@4.2.2...4.3.1)

---
updated-dependencies:
- dependency-name: NUnit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

SpotifyAPI.Web.Tests/SpotifyAPI.Web.Tests.csproj

@@ -11,7 +11,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="Moq" Version="4.20.72" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
-    <PackageReference Include="NUnit" Version="4.2.2" />
+    <PackageReference Include="NUnit" Version="4.3.1" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
     <PackageReference Include="NUnit.Console" Version="3.18.3" />
   </ItemGroup>