chore: run cancel workflow on pull request

Author: ersachin3112

.github/workflows/cancel.yml

@@ -1,7 +1,18 @@
 name: Cancel
-on: [push]
+on:
+  push:
+    branches:
+      - master
+      - next
+  pull_request:
+    branches:
+      - master
+      - next
+permissions: {} # none
 jobs:
   cancel:
+    permissions:
+      actions: write
     name: Cancel Previous Runs
     runs-on: ubuntu-latest
     timeout-minutes: 3