add node version

Author: elenirotsides

.github/workflows/fly-deploy.yml

@@ -9,6 +9,8 @@ jobs:
         steps:
             - name: Checkout code
               uses: actions/checkout@v2
+              with:
+                  node-version: '16.9.1'
 
             - name: Set up Fly CLI
               uses: superfly/flyctl-actions/setup-flyctl@master