Upgrade OS version for base Docker image to jammy (Ubuntu 22)

As of 9.1, the Solr docker image uses focal, Ubuntu 20. This was chosen in SOLR-16486 because docker support for jammy (Ubuntu 22) was only 5 months old at the time. By the time 9.2 is released, the compatible docker version will be > 10 months old, which is a reasonable amount of time to expect people to upgrade within.

The impetus here is that some of our dependencies in the docker image cannot be upgraded to newer versions, because they are stuck at older versions for Ubuntu 20 apt-get. Upgrading to Ubuntu 22 will allow us to also upgrade these dependencies.