Bump Microsoft.Extensions.Hosting

Bumps the dotnet group in /docs/core/extensions/snippets/workers/signal-completion-service/App.SignalCompletionService with 1 update: [Microsoft.Extensions.Hosting](https://github.com/dotnet/runtime).


Updates `Microsoft.Extensions.Hosting` from 8.0.1 to 9.0.0
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v8.0.1...v9.0.0)

---
updated-dependencies:
- dependency-name: Microsoft.Extensions.Hosting
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: dotnet
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/core/extensions/snippets/workers/signal-completion-service/App.SignalCompletionService/App.SignalCompletionService.csproj

@@ -7,6 +7,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.0" />
   </ItemGroup>
 </Project>