Update Travis to use latest Node LTS

[AndrewADev]

Update CI config to use the most recent LTS.

For some other possible values, see: https://docs.travis-ci.com/user/languages/javascript-with-nodejs/#specifying-nodejs-versions

Closes #2305

[AndrewADev]

RE: initial error on this PR (possibly the same one that caused the Node version revert in the first place) - It seems that the default runner version -- 16.04 of Ubuntu:

...doesn't include the glibc versions needed by newer versions of Node. See this comment here

As such, I have set the runner to use Jammy Jellyfish (22.04) for now, which is along the same lines as the suggestions for this error on the Travis CI forums (just slightly newer).

In theory, the named dist can be removed if/when Travis bumps the default OS version to one that uses supported glibc versions. Otherwise, the currently pinned version should be supported several years into the future.

[iangilman]

Awesome. Thank you for doing the leg work to track down an appropriate distro! And thank you for including the comment so we can remember why we did it like this.