.NET 8, Function Decorators Not Recognized

I am attempting to migrate an Azure Function from .NET 6 to .NET 8 and from in-process to isolated.

I followed the instructions outlined here: https://github.com/Azure/azure-functions-openapi-extension/blob/main/docs/enable-open-api-endpoints-out-of-proc.md

Including updating the the csproj and performing `dotnet restore`:

However, it appears that the decorators are still not recognized?

Visual Studio Code indicates: _'OpenApiOperation' is not an attribute class_

I have tried `dotnet clean`, I have tried completely exiting VS Code and restarting.

Start with the linked out-of-process OpenAPI instructions and the project's .csproj changes, then reproduce the decorator error after dotnet restore in Visual Studio Code. Check how OpenApiOperation is referenced and whether it is recognized as an attribute in the .NET 8 isolated setup; done means the decorators compile and the migration instructions work.

Written by the indexing model from the issue text.