Revert "ci: temporarily disable triggers in build workflow until new wdk-build version is ingested"

This reverts commit f054f1f.

Author: wmmc88

.github/workflows/build.yaml

@@ -1,7 +1,6 @@
 on:
   push:
-  # Temporarily disable until new wdk-build version is ingested: https://github.com/microsoft/Windows-rust-driver-samples/pull/46
-  # pull_request:
+  pull_request:
   merge_group:
   schedule: # Trigger a job on default branch at 4AM PST everyday
     - cron: "0 11 * * *"