fix tester workflow

Revert change in #646, from on_pr_target -> on_pr (#692)

Author: dario-coscia

.github/workflows/tester.yml

@@ -1,7 +1,7 @@
 name: "Testing Pull Request"
 
 on:
-  pull_request_target:
+  pull_request:
     branches:
       - "master"
       - "dev"
@@ -75,4 +75,4 @@ jobs:
           threshold: 80.123
           fail: true
           publish: true
-          coverage-summary-title: "Code Coverage Summary"
+          coverage-summary-title: "Code Coverage Summary"