npm update everything (wikimedia-gadgets#1794)

Now that we're finally on the latest version of Jest, it should be safe to update all our npm dependencies.

These are all **dev** dependencies and have no chance of breaking the Twinkle build used on-wiki.

Since these are all dev dependencies, the only testing needed should be 1) make sure CI passes and 2) make sure `npm start` works.

Tested, works.