OEM: IONOS Cloud Images

[tuunit]

Adds IONOS Cloud custom provider

This aims to keep supporting basic Cloud-Init functionality with Flatcar by introducing the IONOS Cloud provider. As the IONOS Cloud was built on top of the idea of cloud-init all of our utilities and customers use it. Therefore we want to have basic feature support to not force everyone to switch to ignition

How to use

Use the IONOS Cloud Flatcar image to create a VM and inject Cloud-Init User Data:

https://docs.ionos.com/cloud/storage-and-backup/block-storage/images-snapshots/boot-cloud-init

Use the #cloud-config directive!

Testing done

Used the Image built from https://github.com/flatcar/scripts/pull/2389 and inject a basic cloud-config script:

#cloud-config

write_files:
  - path: /hello
    content: |
        world!

And checked if the file exists after the first boot.

PR Requirements

• [ ] Changelog entries added in the respective changelog/ directory (user-facing change, bug fix, security fix, update)
• [ ] Inspected CI output for image differences: /boot and /usr size, packages, list files for any missing binaries, kernel modules, config files, kernel modules, etc.