fix: upgrade pylint from pinned 2.13.9 to >=2.13.9

pylint 2.13.9 incorrectly reports os.getenv as E1101 (no-member)
on newer Python. Allow resolution to a newer version that fixes this.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: wu-sheng