DeterminateSystems/nix-installer v3.6.8

on GitHub

What's Changed

• Ditch unnecessary concurrency groups by @grahamc in #1592
• Run the container / vm tests twice if they fail, with a timeout of 10… by @grahamc in #1591
• Release v3.6.8 by @github-actions in #1593

Full Changelog: v3.6.7...v3.6.8