chore: run CI on v4 branch

Author: SimenB

.github/workflows/node.js.yml

@@ -4,9 +4,11 @@ on:
   push:
     branches:
       - main
+      - v4
   pull_request:
     branches:
       - main
+      - v4
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}