Remove non-existent typecheck step from CI/CD

The project is written in JavaScript, not TypeScript, so there's no
typecheck script in package.json. Removing this step prevents CI failures.

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

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

.github/workflows/deploy.yml

@@ -44,9 +44,6 @@ jobs:
       - name: Run tests
         run: npm test
       
-      - name: Run type checking
-        run: npm run typecheck
-      
       - name: Upload coverage
         if: matrix.node-version == '20.x'
         uses: codecov/codecov-action@v3