fix: remove conflicting NPM_TOKEN from Trusted Publishing workflow

[nastassiafulconis]

Summary

• Removes NPM_TOKEN environment variable from release workflow that was causing authentication failures
• The workflow already has id-token: write for Trusted Publishing (OIDC), which conflicts with legacy token authentication
• NPM_TOKEN was accidentally reintroduced in PR Comprehensive CLI improvements and security fixes #21

Root Cause

When both Trusted Publishing (id-token: write) and legacy token authentication (NPM_TOKEN) are configured, npm authentication fails with "ENEEDAUTH" error.

Solution

Remove the NPM_TOKEN environment variable to use only Trusted Publishing for secure, token-free npm publishing.

Test Plan

• Build passes locally
• Tests pass locally
• Verify release workflow succeeds after merge

Related Issues

Fixes the npm publishing failure that started after PR #21 was merged.