Bump NUnit3TestAdapter from 4.3.1 to 4.4.0 in /src

Bumps [NUnit3TestAdapter](https://github.com/nunit/nunit3-vs-adapter) from 4.3.1 to 4.4.0.
- [Release notes](https://github.com/nunit/nunit3-vs-adapter/releases)
- [Commits](nunit/nunit3-vs-adapter@V4.3.1...V4.4.0)

---
updated-dependencies:
- dependency-name: NUnit3TestAdapter
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/AzureIoTHub.Portal.Tests.Unit/AzureIoTHub.Portal.Tests.Unit.csproj

@@ -31,7 +31,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
     <PackageReference Include="Moq" Version="4.18.4" />
     <PackageReference Include="NUnit" Version="3.13.3" />
-    <PackageReference Include="NUnit3TestAdapter" Version="4.3.1" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.4.0" />
     <PackageReference Include="coverlet.collector" Version="3.2.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>