Update actions/upload-artifact action to v4

Author: renovate[bot]

.github/workflows/testing.yml

@@ -77,7 +77,7 @@ jobs:
           make test-cover
 
       - name: Upload coverage
-        uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
+        uses: actions/upload-artifact@5d5d22a31266ced268874388b861e4b58bb5c2f3 # v4.3.1
         with:
           name: coverage
           path: coverage.*