Bump bunit from 1.21.9 to 1.22.19 in /src (#2372)

Bumps [bunit](https://github.com/bUnit-dev/bUnit) from 1.21.9 to 1.22.19.
- [Release notes](https://github.com/bUnit-dev/bUnit/releases)
- [Changelog](https://github.com/bUnit-dev/bUnit/blob/main/CHANGELOG.md)
- [Commits](bUnit-dev/bUnit@v1.21.9...v1.22.19)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/IoTHub.Portal.Tests.Unit/IoTHub.Portal.Tests.Unit.csproj

@@ -16,7 +16,7 @@
   <ItemGroup>
     <PackageReference Include="AutoFixture" Version="4.18.0" />
     <PackageReference Include="Blazored.LocalStorage.TestExtensions" Version="4.3.0" />
-    <PackageReference Include="bunit" Version="1.21.9" />
+    <PackageReference Include="bunit" Version="1.22.19" />
     <PackageReference Include="Docker.DotNet" Version="3.125.15" />
     <PackageReference Include="FluentAssertions" Version="6.11.0" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="7.0.9" />