Fix stale workflow issues (keras-team#2621)

Author: sachinprasadhs

.github/workflows/auto-assignment.yml

@@ -3,6 +3,9 @@ on:
   issues:
     types:
       - opened
+  pull_request_target:
+    types:
+      - opened
 
 permissions:
   contents: read

.github/workflows/stale-issue-pr.yml

@@ -10,6 +10,8 @@ jobs:
     permissions:
       issues: write
       pull-requests: write
+      contents: write
+      actions: write
     steps:
       - name: Awaiting response issues
         uses: actions/stale@v9