Avoid rounding error in `test_prometheus_collect_count_total_by_cost_…

…multipliers` (#8687)

distributed/http/scheduler/tests/test_stealing_http.py

@@ -91,7 +91,7 @@ async def fetch_metrics_by_cost_multipliers():
         for request in event[1]
         if event[0] == "request"
     )
-    assert count == expected_cost
+    assert count == pytest.approx(expected_cost)
 
 
 @gen_cluster(