update PR action to rerun on new commits

Author: tebexjaames

.github/workflows/pr.yml

@@ -5,7 +5,7 @@ name: PR
 on:
     # Triggers the workflow on push or pull request events but only for the master branch
     pull_request:
-      types: [opened, reopened]
+      types: [opened, reopened, synchronize]
 
 jobs:
   test-and-build: