Fix pull-request build CI

Author: alextwoods

.github/workflows/pull-request-build.yml

@@ -1,8 +1,14 @@
 name: Build SDK
 on:
-  pull_request:
   merge_group:
-    types: [opened, synchronize, ready_for_review]
+  pull_request:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - '**.md'
+      - '.all-contributorsrc'
+      - 'docs/**'
 
 concurrency:
   group: start-pull-request-build-${{ github.ref }}