Remove schedule for TagBot

Also based on https://discourse.julialang.org/t/ann-required-updates-to-tagbot-yml/49249

Author: rikhuijzer

.github/workflows/TagBot.yml

@@ -1,7 +1,5 @@
 name: TagBot
 on:
-  schedule:
-    - cron: 0 * * * *
   issue_comment:
     types:
       - created