Functions Core Tools installer does not work with Debian 12, breaking Codespaces/DevContainers

Repro:
1) start with the CodeSpaces/Devcontainer template for .NET (8) here:
https://github.com/codespaces?WT.mc_id=timheuer-blog-timheuer

2) inside the terminal of that container, install Azure Functions Core Tools using the standard instructions:
https://learn.microsoft.com/en-us/azure/azure-functions/functions-run-local?tabs=linux%2Cisolated-process%2Cnode-v4%2Cpython-v2%2Chttp-trigger%2Ccontainer-apps&pivots=programming-language-csharp

The apt-get install won't work and fail finding files for Debian 12. The document also does not list Debian 12.

```bash
@paulyuk ➜ /workspaces/dotnet-codespaces (main) $ cat /etc/apt/sources.list.d/dotnetdev.list
deb [arch=amd64] https://packages.microsoft.com/debian/12/prod bookworm main

@paulyuk ➜ /workspaces/dotnet-codespaces (main) $ sudo apt-get install azure-functions-core-tools-4
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package azure-functions-core-tools-4
```

Request:
Please add apt-get install support for Debian 12, and ensure this e2e scenario works.

Start by reproducing the Debian 12 Codespaces/DevContainer scenario and inspect /etc/apt/sources.list.d/dotnetdev.list before running apt-get install azure-functions-core-tools-4. Compare the standard Linux installation instructions with the Debian 12 package setup. Done means the package installs successfully and the documented end-to-end scenario works.

Written by the indexing model from the issue text.