Update add_to_project.yml

.github/workflows/add_to_project.yml

@@ -5,9 +5,10 @@ on:
     types:
       - opened
       - transferred
-  pull_request:
+  pull_request_target:
     types:
       - opened
+    branches: ['main']
 
 permissions:
   issues: write
@@ -16,7 +17,7 @@ permissions:
 jobs:
   cleanup_old_runs:
       runs-on: ubuntu-20.04
-      if: github.event_name != 'pull_request'
+      if: github.event_name != 'pull_request_target'
       permissions:
         actions: write
       env:
@@ -42,7 +43,7 @@ jobs:
           github-token: ${{ secrets.REPO_PROJECT_PAT }}
   apply-label:
     runs-on: ubuntu-latest
-    if: github.event_name != 'pull_request'
+    if: github.event_name != 'pull_request_target'
     steps:
       - uses: actions/github-script@v6
         with:
@@ -55,7 +56,7 @@ jobs:
             })
   apply-milestone:
     runs-on: ubuntu-latest
-    if: github.event_name != 'pull_request'
+    if: github.event_name != 'pull_request_target'
     steps:
       - uses: actions/github-script@v6
         with: