fix(tests): use CandleType.FUTURES in test_ohlcv_limit_futures

The futures_only ternary incorrectly used CandleType.SPOT for exchanges
that support both spot and futures (binance, gate), causing candle limit
mismatch against candle_count_futures.

tests/exchange_online/test_ccxt_compat.py

@@ -64,8 +64,7 @@ class TestCCXTExchange:
         if not expected_count:
             pytest.skip("No expected candle count for exchange")
 
-        candle_type = CandleType.FUTURES if exchange_params.get("futures_only") else CandleType.SPOT
-        assert exch.ohlcv_candle_limit("1m", candle_type) == expected_count
+        assert exch.ohlcv_candle_limit("1m", CandleType.FUTURES) == expected_count
 
     def test_load_markets_futures(self, exchange_futures: EXCHANGE_FIXTURE_TYPE):
         exchange, _, exchange_params = exchange_futures