Pop!\_OS Packaging CI

WIP Rust rewrite of the CI scripts used in Pop!_OS for automatically generating Debian packages and repositories from the pop-os GitHub organization. Currently requires a beta version of Rust for async/await support.

Checklist

• Fetching all GitHub repos and their branches
• Checking locally-cloned git repos and updating them
• Generating a git tar from each commit for each branch
• Assigning a git tar to each pocket for each codename
• Check if sources have been built
• Build missing sources
• Memorize repos which lack debian directories
• Memorize commits which failed to build.
• Checking if a package has already been built
• Building packages with sbuild
• Creating apt repositories for each pocket and codename
• Setting GitHub statuses
• Launchpad integration