nix: enable esbuild by default

Created by: Strum355

esbuild seems to be the way forward (and honestly its just so much faster), so this seems like a good idea to set as default

Test plan

N/A, dev env

Created by: keegancsmith

Review: Approved

nice, already have this in my .envrc :)

Merged by: Strum355 at 2022-08-23 12:14:45 UTC