fix: remove push trigger

Author: abailly

.github/workflows/cardano-node.yaml

@@ -13,7 +13,6 @@ on:
         required: true
         default: cardano_node_10.4.1
         type: string
-  push:
   schedule:
     # run every 6 hours
     - cron:  '5 1,7,13,19 * * *'