After updating to Webpack 5, I figured I'd update this related package as well.

Depends on D6707

1. I tested dev build in web via yarn dev in web + keyserver and then tested the website
2. I tested prod build by running yarn prod in web and then tested the website by running keyserver with yarn prod-build && yarn-prod
3. I reviewed the releases on GitHub and found two versions with breaking changes listed: 5.0.0 and 6.0.0. Neither seemed to mentioned anything relevant to us