[feat] Add Hetzner Platform

[mnbro]

Flatcar Linux has now prebuilt images for Hetzner Cloud: [RFE] Hetzner support and ARM64 image and x86-64 image.

There is an utility to upload the above mentioned images: hcloud-upload-image

Taking into consideration all the above, is it possible to add Hetzner Platform for Flatcar Linux both arm64 and x86-64?

[dghubble]

Developing support for a new platform and supporting it over time has significant time and infra costs. And to maintain quality, we'd need to be operating on Hetzner regularly. This would require long-term Hetzner sponsorship like was done with DigitalOcean.