ci: update changelog

.github/workflows/changelog.yml

@@ -3,14 +3,13 @@ on:
   pull_request:
     types:
       - closed
+  workflow_dispatch:
 
 jobs:
   changelog:
     name: Generate changelog
     if: ${{ github.event.pull_request.merged }}
     runs-on: ubuntu-latest
-    permissions:
-      contents: write
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4