chore: remove js-green-licenses

[rachel-fenichel]

The basics

• I branched from develop
• My pull request is against develop
• My code follows the style guide
• I ran npm run format and npm run lint

The details

Resolves

Proposed Changes

Remove the js-green-licenses package and references to it.

Behavior Before Change

We had a manually-executable gulp command to check licenses, which we never used.

Behavior After Change

No license command, and a slightly smaller dependency tree.

Reason for Changes

There are other ways to check licenses for a package, that don't involve pulling this into our dev dependencies.

Additional Information

This does not need to land before the next release--I can always rebase it--but it shouldn't break anything since it was all unused.

[cpcallen]

I'm guessing that all this can be replaced with a single npx js-green-licenses <some additional args?> call. Might it be worth documenting that in our (internal or external) documentation?

Or maybe keep the license script in package.json but have it use npx?

[rachel-fenichel]

Given that I have no record of us using the license check in automated or manual releases, I'd rather just delete it.