Fix node-version formatting for consistency with other workflows

Co-authored-by: jaredmixpanel <[email protected]>

Author: Copilot

.github/workflows/copilot-setup-steps.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Set up Node.js 20.x
         uses: actions/setup-node@v5
         with:
-          node-version: '20'
+          node-version: 20
           cache: 'npm'
 
       - name: Install dependencies