fix: use repository variable instead of secret for AWS_DEPLOYMENT_ROLE

Changed from secrets.AWS_DEPLOYMENT_ROLE to vars.AWS_DEPLOYMENT_ROLE to correctly reference the repository variable

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

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

Author: PaulDuvall

.github/workflows/npm-publish-simple.yml

@@ -27,7 +27,7 @@ jobs:
       - name: Configure AWS credentials
         uses: aws-actions/configure-aws-credentials@v4
         with:
-          role-to-assume: ${{ secrets.AWS_DEPLOYMENT_ROLE }}
+          role-to-assume: ${{ vars.AWS_DEPLOYMENT_ROLE }}
           aws-region: us-east-1
 
       - name: Store NPM token in SSM