Fix metrics test

Author: sfc-gh-jkew

modin/tests/test_metrics.py

@@ -88,10 +88,12 @@ def test_metrics_handler_fails(metric_client):
 
 def test_emit_name_enforced():
     try:
+        MetricsMode.enable()
         emit_metric("Not::A::Valid::Metric::Name", 1.0)
     except KeyError:
         # error expected
-        pass
+        return
+    assert False
 
 
 def test_metrics_can_be_opt_out(metric_client):