Update dependabot-bot.yml (dotnet#31743)

Author: IEvangelist

.github/workflows/dependabot-bot.yml

@@ -16,6 +16,10 @@ on:
 jobs:
   dependabot-bot:
     runs-on: ubuntu-latest
+    permissions:
+        contents: write
+        pull-requests: write
+    
     # Checkout the repo into the workspace within the VM
     steps:
     - uses: actions/checkout@v3