refactor: remove funding_fee_candle_limit override

Kraken Futures now provides 1 year of hourly funding rate history.
The previous limit of 700 candles (29 days) was a workaround for
limited API retention. Freqtrade paginates funding rate fetches
automatically, so the CCXT default (2000) works correctly.

tests/exchange/test_krakenfutures.py

@@ -35,8 +35,6 @@ def test_krakenfutures_ft_has_overrides():
     assert ft_has["stoploss_query_requires_stop_flag"] is True
     assert ft_has["stop_price_param"] == "triggerPrice"
     assert ft_has["stop_price_type_field"] == "triggerSignal"
-    # Kraken retains only ~29 days of hourly funding rate history
-    assert ft_has["funding_fee_candle_limit"] == 700
 
 
 def test_krakenfutures_ohlcv_candle_limit_uses_ccxt_limit(mocker, default_conf):
@@ -49,15 +47,6 @@ def test_krakenfutures_ohlcv_candle_limit_uses_ccxt_limit(mocker, default_conf):
     assert ex.ohlcv_candle_limit("1m", candle_type=CandleType.FUTURES) == 2000
 
 
-def test_krakenfutures_ohlcv_candle_limit_funding_rate(mocker, default_conf):
-    """Funding rate candle limit is capped to reflect Kraken's limited history retention."""
-    ex = get_patched_exchange(mocker, default_conf, exchange="krakenfutures")
-
-    mocker.patch.object(ex, "features", return_value=2000)
-
-    assert ex.ohlcv_candle_limit("1h", candle_type=CandleType.FUNDING_RATE) == 700
-
-
 # --- _order_contracts_to_amount trigger price fix tests ---