ci: Bump download-artifact from v3 to v4

Author: mrbazzan

.github/workflows/test.yml

@@ -59,7 +59,7 @@ jobs:
         run: python -m pip install --upgrade coverage[toml]
 
       - name: Download data
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: coverage-data