restore axe_core level to minor

tests/end_to_end/conftest.py

@@ -33,5 +33,5 @@ def check_axe_report(page):
     # so we can set the level we skip to minor only
     for violation in results["violations"]:
         assert violation["impact"] in [
-            "minor", "moderate"
+            "minor"
         ], f"Accessibility violation: {violation}"