Bump Testcontainers from 3.6.0 to 3.9.0

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] <[email protected]>

Base/src/ThingsLibrary.Testing/ThingsLibrary.Testing.csproj

@@ -20,7 +20,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="MSTest.TestFramework" Version="3.1.1" />
-		<PackageReference Include="Testcontainers" Version="3.6.0" />
+		<PackageReference Include="Testcontainers" Version="3.9.0" />
 	</ItemGroup>
 
 	<ItemGroup>