The recently added generate-emoji-txt.sh script uses a Bash 4
substitution feature, causing CI to fail as macOS ships an ancient Bash
3.x. We'll want to use a more recent version anyway, so let's do that
instead of updading the script to older syntax.
This commit upgrades Github Actions workers to ubuntu-22.04
As part of that change, we (currently) no longer need the backports
nor toolchain-r/test PPAs, because ubuntu-22.04 include
recent-enough version of QEMU and gcc
Now that clang-format-14 ubuntu packages are available, it's time to
finally upgrade our clang-format version. This version brings with it
a bunch of useful features with const-placement being the most notable.
These will be enabled in the following commits.