chore: remove NPM_AUTH_TOKEN from release workflow

Now using npm trusted publishing with provenance, so the NPM_AUTH_TOKEN environment variable is no longer needed. The workflow already has the necessary permissions (id-token: write) and uses the --provenance flag for secure publishing.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jkebinger

.github/workflows/release.yaml

@@ -53,8 +53,6 @@ jobs:
       id-token: write
     outputs:
       published-version: ${{ needs.check-version.outputs.current-version }}
-    env:
-      NPM_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
     steps:
       - uses: actions/checkout@v4
       # Setup .npmrc file to publish to npm