GCP User IAM workflow, include pull request types reference

Author: ksobrenat32

.github/workflows/beam_Infrastructure_UsersPermissions.yml

@@ -31,6 +31,7 @@ on:
     paths:
       - 'infra/iam/users.yml'
   pull_request_target:
+    types: [opened, synchronize, reopened]
     paths:
       - 'infra/iam/users.yml'
 
@@ -51,6 +52,8 @@ jobs:
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
       - name: Setup gcloud
         uses: google-github-actions/setup-gcloud@v3
       - name: Install Terraform