[update-versions.yml] Implement least privilege permissions

- Add empty permission set at workflow level
- Remove contents:write from job, add to GitHub App token

.github/workflows/update-versions.yml

@@ -3,6 +3,8 @@ name: Update Versions
 on:
   workflow_dispatch:
 
+permissions: {}
+
 jobs:
   setup:
     name: Setup
@@ -101,7 +103,6 @@ jobs:
     runs-on: ubuntu-24.04
     needs: setup
     permissions:
-      contents: write
       id-token: write
     steps:
       - name: Log in to Azure
@@ -127,6 +128,8 @@ jobs:
         with:
           app-id: ${{ steps.get-kv-secrets.outputs.BW-GHAPP-ID }}
           private-key: ${{ steps.get-kv-secrets.outputs.BW-GHAPP-KEY }}
+          permission-contents: write
+
 
       - name: Checkout Branch
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0