set build workflow to run on push and PR event

.github/workflows/build.yaml

@@ -1,16 +1,16 @@
 name: Setup and build packages
 
 # To manually run the workflow on GH, use the workflow_dispatch event trigger
-on: workflow_dispatch
+# on: workflow_dispatch
 
 # To automatically run on every push to GH, use the push and pull_request event trigger
-# on:
-#   push:
-#     branches:
-#       - main
-#   pull_request:
-#     branches:
-#       - main
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
 
 env:
   USER: github.actor