Parallel deploy jobs on the shared self-hosted host raced on
/home/runner/setup-pnpm (ENOTEMPTY / missing tarball errors).
Use penpotapp/devenv, which already ships the Node and pnpm versions
pinned in develop, and mount a persistent pnpm store from the host
instead of pnpm/setup + actions/cache.
Signed-off-by: David Barragán Merino <david.barragan@kaleidos.net>