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]

Directory.Packages.props

@@ -19,7 +19,7 @@
     <PackageVersion Include="System.CommandLine.DragonFruit" Version="0.4.0-alpha.25320.106" />
     <!-- Reference-only packages for test framework namespace resolution in analyzer tests -->
     <PackageVersion Include="xunit.v3.core" Version="3.2.2" />
-    <PackageVersion Include="NUnit" Version="4.5.1" />
+    <PackageVersion Include="NUnit" Version="4.6.0" />
     <PackageVersion Include="TUnit.Core" Version="1.40.10" />
   </ItemGroup>
 </Project>