Upgrade CI to min ubuntu 20.04

[rukai]

Only upgrading to ubuntu 20.04 instead of directly to 22.04 to maintain compatibility with 20.04 in our binary builds.

I chose to create a .deb rather than directly mashing the files into /usr/lib so that:

• local users have a way to uninstall the package.
• caching just works:
  • we tell GA to cache the packages folder and then it will cache every package that gets built
    • built packages are really small, ~1MB for this one, so we dont need to worry about excessive cache usage.
    • packages are versioned so we dont have to worry about the cache accidentally pulling in an old version of cassandra-cpp-driver.

Alternatives:

1

Publish packages somewhere and wget them like we do currently with the datastax packages.
I didnt take this approach as we need somewhere to host them and it is a lot of extra work to package them every time a new release occurs that we want to use.

2

Annoy datastax into publishing packages for a modern ubuntu.
Not sure if they care enough about the cpp driver for that, and even if they did, we would still need to reannoy them in the future when a new ubuntu comes out.

3

Force installation of the 18.04 package onto a modern ubuntu.
I tested this and it doesnt work at all.
We can succesfully install the package with dpkg --force-install -i ....
However when we try to build the project it fails with linker errors.

References:

• Followed this guide to create the package https://ubuntuforums.org/showthread.php?t=910717
• I reused the naming scheme of the old packages: https://downloads.datastax.com/cpp-driver/ubuntu/18.04/cassandra/v2.16.0/
• I used the AUR package as a reference for how to build the project: https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=cassandra-cpp-driver

[benbromhead]

I'm so mad at this dependency right now... this seems like the easiest path forward right now. In the mean time imma bug datastax