Delete other/date_to_weekday.py as a how-to-use, not an algorithm (#5591)

* [mypy] Fixes typing errors in other/date_to_weekday

* [mypy] uses future annotation style for other/date_to_weekly

* date_to_weekday: new implementation replaces buggy original

* date_to_weekday: add examples from multiple of 100 years

* clean-up: runs `black` to fix formatting

* Delete date_to_weekday.py
Co-authored-by: NChristian Clauss <cclauss@me.com>

other/date_to_weekday.py

-from calendar import day_name
-from datetime import datetime
-
-
-def date_to_weekday(inp_date: str) -> str:
-    """
-    It returns the day name of the given date string.
-    :param inp_date:
-    :return: String
-    >>> date_to_weekday("7/8/2035")
-    'Tuesday'
-    >>> date_to_weekday("7/8/2021")
-    'Saturday'
-    >>> date_to_weekday("1/1/2021")
-    'Friday'
-    """
-    day, month, year = (int(x) for x in inp_date.split("/"))
-    if year % 100 == 0:
-        year = "00"
-    new_base_date: str = f"{day}/{month}/{year%100} 0:0:0"
-    date_time_obj: datetime.date = datetime.strptime(new_base_date, "%d/%m/%y %H:%M:%S")
-    out_put_day: int = date_time_obj.weekday()
-    return day_name[out_put_day]
-
-
-if __name__ == "__main__":
-    print(date_to_weekday("1/1/2021"), end=" ")