ci: Use pull_request_target event

.github/workflows/close-master-prs.yml

@@ -1,10 +1,12 @@
 name: Close PRs to master
 
 on:
-  pull_request:
+  pull_request_target:
     types: [opened, reopened, synchronize, edited]
     branches:
       - master
+    branches-ignore:
+      - new-pr
   workflow_dispatch:
 
 permissions:
@@ -24,7 +26,7 @@ jobs:
             fi
           fi
         env:
-          GITHUB_TOKEN: ${{ secrets.FLATHUBBOT_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           REPO: flathub/flathub
           COMMENT: >
               This PR is automatically closed because application submission