Disable GitHub Actions workflows (#675)

Move .github/workflows/*.yml(.yaml) to .github/workflows-disabled/ to neutralize
them ahead of the org-wide GitHub Actions enablement. Restore via the
re-enable-workflow process when a workflow is intentionally re-enabled.

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

Author: eredi93