Updating bionic, focal and jammy cl-repro builds:
- Rust version from 1.62 to 1.65
- Removed git clone, only mount option
- Removed sha256sums generation
Switching to poetry, and deprecating python 3.6, made things a bit
more tricky. Sadly we'll not be able to build jammy, as its support is
missing in the tag tarball, but it'll be there for the next release.