Use gardenlinux apt repo

[Vincinator]

• Use Garden Linux repo
• install gcc from debian testing. always build latest and greatest compiler
• use silent mode of nvidia installer to avoid need of user interaction and tui dependencies
• set apt pin to correct garden linux dist (version e.g. 934.10)
• use latest build tools from garden linux today
• Use kernel meta packages to identify correct kernel environment

[gardener-robot]

@Vincinator Thank you for your contribution.