Current Node version pipelines fail due to Travis dependency issues

[pbredenberg]

Travis pipelines for Node.js v18.x fail with:

node: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.27' not found (required by node)
node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.25' not found (required by node)
node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by node)
The command "npm config set spin false" failed and exited with 1 during .

This appears to be a known issue: https://travis-ci.community/t/the-command-npm-config-set-spin-false-failed-and-exited-with-1-during/12909

For now, I've disabled the latest node step in the pipeline config, and will reenable later when the problem has been resolved.

[pbredenberg]

Looks like the solution here is to declare: dist: focal as the Ubuntu distribution image of choice for our images. This problem above is related to Node.js's official compiler strategy:

nodejs/node#42351 (comment)

includes a glibc version bump that excludes Ubuntu 18.04

A forward-looking approach is to go ahead and advance our builds to run on Ubuntu 20.x