Bump actions/download-artifact from 5 to 6 (#210)

Author: dependabot[bot]

.github/workflows/wheels.yml

@@ -105,7 +105,7 @@ jobs:
     if: github.event_name == 'release' && github.event.action == 'published'
     steps:
       - name: Download artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           # unpacks all CIBW artifacts into dist/
           pattern: cibw-*