ci: remove advanced CodeQL workflow in favor of default setup

The advanced workflow's SARIF upload failed with a configuration error
('Code scanning is not enabled for this repository') because code scanning
was never initialized for this repo. For a small pure-Python package, GitHub
default setup is the recommended, zero-maintenance path; the custom workflow
added nothing this repo needs (no custom build/queries/languages).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: musharna