Bump bunit from 1.17.2 to 1.18.4 in /src (#1820)

Bumps [bunit](https://github.com/bUnit-dev/bUnit) from 1.17.2 to 1.18.4.
- [Release notes](https://github.com/bUnit-dev/bUnit/releases)
- [Changelog](https://github.com/bUnit-dev/bUnit/blob/main/CHANGELOG.md)
- [Commits](bUnit-dev/bUnit@v1.17.2...v1.18.4)

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

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

src/AzureIoTHub.Portal.Tests.Unit/AzureIoTHub.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="1.17.2" />
+    <PackageReference Include="bunit" Version="1.18.4" />
     <PackageReference Include="Docker.DotNet" Version="3.125.12" />
     <PackageReference Include="FluentAssertions" Version="6.10.0" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="7.0.3" />