Update build/CI automation to use ubuntu-20.04

[philrz]

We've been using the ubuntu-18.04 platform for some time to test and build Brim. Recent notifications from GitHub have indicated:

The official deprecation notice is here.

In reaction to this, I plan to:

1. Create test builds using the ubuntu-20.04 Actions Runners
2. Smoke test it on older Linux releases
3. Make any necessary updates to our support statement at https://github.com/brimdata/brim/wiki/Supported-Platforms
4. Advance our Actions Workflow YAML configs to start using the ubuntu-20.04 Actions Runners going forward

[philrz]

Zui artifacts used for testing are here. Similar to what was done in #1263, testing proceeded like a binary search to find the oldest & newest versions of key Linux distros that passed a smoke test out-of-the-box.

The tl;dr of the results is that the artifacts now built in Actions with ubuntu-20.04 rely on a newer GLIBC version, which causes us to drop support for some older releases. The exercise also made me aware of the RHEL-related drama that motivated a move to testing Rocky Linux as the RHEL-compatible platform. Finally, issue #2485 was also found and fixed along the way.

Below are the detailed results.

Ubuntu

Ubuntu 18.04: Fail

Ubuntu 20.04: Pass

Ubuntu 22.04.1: Pass

CentOS

CentOS 8 1904: Pass

This was re-tested because it was previously listed in our support statement as the oldest RHEL-compatible release on which Brim successfully passed a smoke test. Since that time, however, the CentOS 8 releases have all been deprecated and the ISO images pulled from mirror sites. I was only able to re-test with this release because I'd saved an old ISO from prior testing. Therefore I intend to stop testing with CentOS going forward and use Rocky Linux instead.

Rocky

Rocky 8.3: Pass

Rocky 9.0: Pass

Fedora

Fedora 28: Fail

Fedora 29: Pass

Fedora 30: Pass

Fedora 32: Pass

Fedora 36: Pass

Debian

Debian 10.0.0: Pass

For some reason, I was unable to install Wireshark on this platform due to issues with dependencies. Strictly speaking, this is orthogonal to the ability to install and use Brim, but I'd been installing Wireshark in all tests as part of confirming that pcap slice extraction was working correctly. In this case the slice extraction was successful and got to the point where a menu of helper apps was presented to open the slice, so this seems close enough to success.

Debian 11.4.0: Pass