Update ci.yml (#7)

Author: fd

.github/workflows/ci.yml

@@ -1,7 +1,7 @@
 name: CI
 
 on:
-  push:
+  pull_request:
   merge_group:
 
 jobs:
@@ -12,4 +12,4 @@ jobs:
       - name: Run a one-line script
         run: |
           echo "Hello, world!"
-          sleep 90
+          sleep 30