Bump NUnit from 4.5.1 to 4.6.0

---
updated-dependencies:
- dependency-name: NUnit
  dependency-version: 4.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

tests/PVOutput.Net.Tests/PVOutput.Net.Tests.csproj

@@ -11,7 +11,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="NSubstitute" Version="5.3.0" />
-    <PackageReference Include="NUnit" Version="4.5.1" />
+    <PackageReference Include="NUnit" Version="4.6.0" />
     <PackageReference Include="NUnit.Analyzers" Version="4.12.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>