WIP: drop parallel-webpack in favor of using webpack directly

[floryst]

Goal: speed up examples building

Could revisit this with vite instead (but would need to work with #3255)

Things that need to be addressed:

• npm run example runner
• markdown/documentation site entry generation

[daker]

I think it’d be great if we switched to Vite and phased out the UMD build.

[floryst]

Agreed. I'm mostly pushing this for reference, but vite would be the way to go down the road.