fix: Bump various versions to remove vulnerable dependencies

[ibacher]

I said I would work on updating the dependencies here. This is the first pass at it, designed to be very low-touch. Specifically the goal of this PR is resolve as many results reported from pnpm audit without moving to dependencies that are incompatible with Node 12, Webpack 4, etc., and this does that, with one exception, which results from serve depending on a version of minimatch that has a ReDoS issue in the generated configs.

In a near-future follow-on, I'll introduce changes that:

• Require Node 14 or 16 at a minimum
• Require Webpack 5

[joeldenning]

If the build passes, this looks good, thanks for your help. Please ping me on Slack in #core-team or #maintainers for the time being when there's a PR to review - my github queue is too large/stressful atm. I've added you as a maintainer to this repo so that your PRs automatically have the build run.