Bump Testcontainers from 3.6.0 to 3.9.0 in /site

Bumps [Testcontainers](https://github.com/testcontainers/testcontainers-dotnet) from 3.6.0 to 3.9.0.
- [Release notes](https://github.com/testcontainers/testcontainers-dotnet/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-dotnet/blob/develop/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-dotnet@3.6.0...3.9.0)

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

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

Author: dependabot[bot]

site/Directory.Packages.props

@@ -49,7 +49,7 @@
     <PackageVersion Include="MudBlazor" Version="6.20.0" />
     <PackageVersion Include="Scriban" Version="5.10.0" />
     <PackageVersion Include="SixLabors.ImageSharp" Version="3.1.4" />
-    <PackageVersion Include="Testcontainers" Version="3.6.0" />
+    <PackageVersion Include="Testcontainers" Version="3.9.0" />
     <PackageVersion Include="Testcontainers.MongoDb" Version="3.6.0" />
     <PackageVersion Include="xunit" Version="2.9.0" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2">