Update Linux kernel to 6.12 and Debian distribution to Bookworm

[Encotric]

Hi,

Thank you for your great work! I started using your development kit for some student work. Therefore, I updated the used kernel to the latest version (6.12) and switched from Debian Bullseye to Debian Bookworm, which required a few changes in your scripts.

Maybe you would like to use this PR to update the repository :)