Update upload-artifact action

Author: erocarrera

.github/workflows/tests.yaml

@@ -54,7 +54,7 @@ jobs:
 
       - if: ${{matrix.coverage}}
         name: "Upload coverage data"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: covdata
           path: .coverage.*