Remove 5 AM cron job from sync-leetcode workflow

Removed redundant cron schedule entry.

Author: NinePiece2

.github/workflows/sync-leetcode.yml

@@ -5,7 +5,6 @@ on:
   schedule:
     - cron: "0 4 * * *"
     - cron: "0 16 * * *"
-    - cron: "0 5 * * *"
 
 jobs:
   build: