Update nightly-pr-close.yml
diff --git a/.github/workflows/nightly-pr-close.yml b/.github/workflows/nightly-pr-close.yml
index 809df0a..a5648d7 100644
--- a/.github/workflows/nightly-pr-close.yml
+++ b/.github/workflows/nightly-pr-close.yml
@@ -4,8 +4,6 @@
   schedule:
     - cron: "0 4 * * *"
 
-on: pull_request
-
 jobs:
   close PRs:
     runs-on: ubuntu-latest