Replace clean.sh files with extra_artifacts mark

The artifact lists in clean.sh and extra_artifacts might be slightly
different. The list was updated for each test to reflect the current
state.

(cherry picked from commit 7c259fe254)

bin/tests/system/emptyzones/tests_sh_emptyzones.py

@@ -9,6 +9,14 @@
 # See the COPYRIGHT file distributed with this work for additional
 # information regarding copyright ownership.
 
+import pytest
+
+pytestmark = pytest.mark.extra_artifacts(
+    [
+        "dig.out.*",
+    ]
+)
+
 
 def test_emptyzones(run_tests_sh):
     run_tests_sh()