test: optimize total Travis run time

* skip compilation by using cache
* split testing into two jobs
* DRY with YAML anchors

PR-URL: https://github.com/nodejs/node/pull/27182
Refs: https://github.com/nodejs/node/pull/27158


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>