Remove duplicate OpenSSF Scorecard workflow (scorecard-enforcer.yml)

scorecard-enforcer.yml runs a second, self-contained OpenSSF Scorecard
scan that duplicates the scan already performed by scorecard.yml, which
delegates to the shared hyperpolymath/standards scorecard reusable
workflow. The governance "Check Workflow Staleness" gate explicitly
requires removing this legacy file. The single reusable-workflow scan
in scorecard.yml is retained.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0196movYBRwNw8vkLRaaFoTu

Author: claude