fix aws s3 sync failing

Author: umbynos

.github/workflows/generate-index.yml

@@ -76,3 +76,5 @@ jobs:
 
       - name: s3 sync
         run: ./s3Copy.sh . s3://arduino-downloads-prod-beagle/arduino-fwuploader
+        env:
+          AWS_REGION: "us-east-1" # or https://github.com/aws/aws-cli/issues/5623