chore(ci): automaticaly trigger aws build on commit push in pr

.github/workflows/build_on_pr_push.yml

@@ -0,0 +1,20 @@
+# Trigger an AWS build each time commits are pushed to a pull request.
+name: PR AWS build trigger
+
+on:
+  pull_request:
+    types:
+      - synchronize
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: mshick/add-pr-comment@v2
+        with:
+          allow-repeats: true
+          message: |
+            @slab-ci cpu-build
+            @slab-ci gpu-build