Update actions/download-artifact action to v6

Author: renovate[bot]

.github/workflows/blank.yml

@@ -46,7 +46,7 @@ jobs:
       runs-on: ubuntu-latest
 
       steps:
-        - uses: actions/download-artifact@v5.0.0
+        - uses: actions/download-artifact@v6.0.0
           with:
             pattern: AppImage-*
             merge-multiple: true