Increase thresholds for cost coverage test for zero-signed fee orders (#96)

This PR attempts to reduce the very noisy errors of the cost coverage
test.

Author: harisang

src/monitoring_tests/cost_coverage_zero_signed_fee.py

@@ -64,7 +64,9 @@ def cost_coverage(self, competition_data: dict[str, Any], gas_cost: float) -> bo
             )
             total_fee += fee
         if total_fee - gas_cost > 0.002 or total_fee - gas_cost < -0.002:
-            if zero_signed_fee_market:
+            if zero_signed_fee_market and (
+                total_fee - gas_cost > 0.02 or total_fee - gas_cost < -0.01
+            ):
                 self.alert(
                     f'"Fees - gasCost" is {total_fee - gas_cost} \
                         for {competition_data["transactionHash"]}.'