Temporarily refer to the 8.0 sample app (#34124)

Author: guardrex

aspnetcore/blazor/tutorials/movie-database-app/index.md

@@ -47,6 +47,11 @@ For Microsoft Azure services, we recommend using *managed identities*. Managed i
 
 If you don't intend to create the demonstration app while reading the article, you can refer to the completed sample app in the [Blazor samples GitHub repository (`dotnet/blazor-samples`)](https://github.com/dotnet/blazor-samples). Select the latest version folder in the repository. The sample folder for this tutorial's project is named `BlazorWebAppMovies`.
 
+<!-- UPDATE 9.0 Revert when the framework is patched. -->
+
+> [!CAUTION]
+> A regression prevents the .NET 9.0 framework from working for this tutorial series at this time. When examining the code in the sample app or obtaining the sample app to run locally, use the .NET 8 version of the sample in the sample repository's `8.0` folder at this time.
+
 ## Article code examples
 
 The line breaks of code examples shown in the ASP.NET Core documentation often don't match line breaks in scaffolded code generated by tooling for an app. This is due to an article publishing limitation. Lines of code in articles are generally limited to 85 characters in length, and we manually adjust the line length using line breaks to satisfy our publishing guidelines.