Update dependency NUnit to 4.4.0 (#5100)

Co-authored-by: dependencyupdates[bot] <218638057+dependencyupdates[bot]@users.noreply.github.com>

Author: dependencyupdates[bot]

src/Directory.Packages.props

@@ -51,7 +51,7 @@
     <PackageVersion Include="NServiceBus.Transport.SqlServer" Version="8.1.9" />
     <PackageVersion Include="NServiceBus.Transport.PostgreSql" Version="8.1.9" />
     <PackageVersion Include="NuGet.Versioning" Version="6.14.0" />
-    <PackageVersion Include="NUnit" Version="4.3.2" />
+    <PackageVersion Include="NUnit" Version="4.4.0" />
     <PackageVersion Include="NUnit.Analyzers" Version="4.7.0" />
     <PackageVersion Include="NUnit3TestAdapter" Version="5.0.0" />
     <PackageVersion Include="OpenTelemetry.Exporter.Console" Version="1.9.0" />