Fix gh-aw version mismatch and regenerate lock file with v0.68.3

- Fix copilot-setup-steps.yml: version v0.42.17 -> v0.68.3 to match action tag
- Regenerate codegen-agentic-fix.lock.yml with real gh aw compile v0.68.3
  (previous lock file was fabricated by agent due to firewall blocking)

Author: edburns