Bump nunit from 3.12.0 to 3.13.0 in /tests/StackInjector.TEST.BlackBox

Bumps [nunit](https://github.com/nunit/nunit) from 3.12.0 to 3.13.0.
- [Release notes](https://github.com/nunit/nunit/releases)
- [Changelog](https://github.com/nunit/nunit/blob/master/CHANGES.md)
- [Commits](nunit/nunit@v3.12...v3.13)

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

Author: dependabot[bot]

tests/StackInjector.TEST.BlackBox/StackInjector.TEST.BlackBox.csproj

@@ -18,7 +18,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="nunit" Version="3.12.0" />
+    <PackageReference Include="nunit" Version="3.13.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.17.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>