chore: remove unused argument time_in_ratio

It was there in preparation for kraken, but kraken
doesn't seem to have this anymore.

Author: xmatthias

freqtrade/exchange/exchange.py

@@ -3934,7 +3934,6 @@ def calculate_funding_fees(
         is_short: bool,
         open_date: datetime,
         close_date: datetime,
-        time_in_ratio: float | None = None,
     ) -> float:
         """
         calculates the sum of all funding fees that occurred for a pair during a futures trade
@@ -3944,7 +3943,6 @@ def calculate_funding_fees(
         :param is_short: trade direction
         :param open_date: The date and time that the trade started
         :param close_date: The date and time that the trade ended
-        :param time_in_ratio: Not used by most exchange classes
         """
         fees: float = 0