Bump NUnit from 4.3.2 to 4.4.0

---
updated-dependencies:
- dependency-name: NUnit
  dependency-version: 4.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Directory.Packages.props

@@ -13,7 +13,7 @@
     <PackageVersion Include="Microsoft.Identity.Client" Version="4.72.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.0" />
     <PackageVersion Include="NSubstitute" Version="5.3.0" />
-    <PackageVersion Include="NUnit" Version="4.3.2" />
+    <PackageVersion Include="NUnit" Version="4.4.0" />
     <PackageVersion Include="NUnit.Analyzers" version="4.8.1" />
     <PackageVersion Include="NUnit3TestAdapter" version="5.0.0" />
     <PackageVersion Include="Refit" Version="8.0.0" />