refactor: tests - update timezone.utc to UTC

tests/exchange/test_gate.py

@@ -1,4 +1,4 @@
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from unittest.mock import MagicMock
 
 import pytest
@@ -113,7 +113,7 @@ def test_fetch_my_trades_gate(mocker, default_conf, takerormaker, rate, cost):
     )
     exchange = get_patched_exchange(mocker, default_conf, api_mock=api_mock, exchange="gate")
     exchange._trading_fees = tick
-    trades = exchange.get_trades_for_order("22255", "ETH/USDT:USDT", datetime.now(timezone.utc))
+    trades = exchange.get_trades_for_order("22255", "ETH/USDT:USDT", datetime.now(UTC))
     trade = trades[0]
     assert trade["fee"]
     assert trade["fee"]["rate"] == rate