use ci-deploy for CI: skip pico8/python3, deploy pre-built artifacts
make deploy rebuilds from source (shrinko8 + pico8), which can't run in a
headless CI container. ci-deploy assembles from committed picosky*.js / .p8
artifacts and calls wrangler directly — no python3 or pico8 needed.
Also removes pnpm from nixery deps (no pnpm install step needed for npx wrangler).