After `better-sqlite3` added support for pre-compiled binaries in
https://github.com/JoshuaWise/better-sqlite3/releases/tag/v6.0.0, we no
longer need to install a compiler toolchain to run `npm install` in our
Docker images.

pelias/docker-baseimage#23 is workong on
removing the compiler toolchain from our Pelias baseimages. In order for
the toolchain to be removed from the whosonfirst image in particular, we
also need to remove those dependencies here.

Until that PR is merged, this change is effectively a no-op. After,
between the two PRs we reduce the size of the whosonfirst docker image
from 490MB to 261MB, an impressive 221MB savings!

Remove unnecessary compiler toolchain dependencies

This is an empty commit that serves only to tell our CI to build new Docker
images now that we have merged pelias/docker-baseimage#24 and move the
default Node.js version from 12 to 16

Connects pelias/pelias#950

This updates CI configuration for this repo with the following changes:
- the core configuration for running unit tests is moved to _test.yml so it
  can be shared
- a new pull request workflow is added that only runs on external forks, and runs unit tests
- Ubuntu versions are now pulled from a GitHub Actions variable (see pelias/pelias#951)

CI: Update GitHub Actions config for uniformity

This is a no-op commit that simply serves to trigger CI to rebuild the
Docker image with our new Ubuntu 22 baseimage

pelias/pelias#951

This helps with support for newer Node.js versions
(pelias/pelias#950)

Upgrade `better-sqlite3` to v8.5.0

Avoid crash during import by bumping memory limit to 8GB

Part of pelias/pelias#801
Technique cribbed from pelias/openaddresses#457

add support elasticsearch v8

BREAKING CHANGE: Pelias no longer supports elasticsearch v6

This change drops support for elasticsearch v6 in order to support v8.
The current recommended version remains v7.