chore: remove duplicate Create Release workflow

create-release-pr.yml and create-release.yml both had name: "Create Release",
causing two identical entries in the Actions tab. The latter is the newer,
cleaner version (tag-only push, no changelog commit to main). Removing the
older one.

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

Author: markhallen