release 6.2.3: add env to disable worker pool

Signed-off-by: Tuan Anh Tran <me@tuananh.org>

bump version to v6.2.2

release: 6.2.1 - release to npm with provenance

Update release.yaml

ci: rebuild with latest emsdk to fix issue with node 18 & fetch

- restore compat with old node version (< 12)

chore release:

- update deps
- update pugixml from upstream

chore release: update deps

fix: add worker.js to files in package.json

- remove .ready() method

- drop support for Node < 12
- use worker_threads (avail from Node >=12)