ci: script to update everything can produce good commit messages

.github/workflows/zen-update.yml

@@ -16,7 +16,7 @@ jobs:
       - name: Check if update is needed
         id: check
         run: |
-          .github/check-update.sh
+          .github/update.sh --ci --only-check
 
       - name: Install Nix
         if: steps.check.outputs.should_update == 'true'
@@ -29,13 +29,14 @@ jobs:
         uses: DeterminateSystems/magic-nix-cache-action@main
 
       - name: Update versions
+        id: update
         if: steps.check.outputs.should_update == 'true'
         run: |
-          .github/update.sh
+          .github/update.sh --ci
 
       - name: Commit changes
         if: steps.check.outputs.should_update == 'true'
         uses: stefanzweifel/git-auto-commit-action@v5
         with:
-          commit_message: "Update Zen Browser to v${{ steps.new-version.outputs.upstream }}"
+          commit_message: "${{ steps.update.outputs.commit_message }}"
           file_pattern: "*"