Errors found in `functions_advanced`

[edoardob90]

There is a lingering datetime.utcnow() in the section about mutable objects as function's arguments:

from datetime import datetime

def log(msg, *, dt=datetime.utcnow()):
    print(f"{dt}: {msg}")

Should be:

from datetime import datetime, UTC


def log(msg, *, dt=datetime.now(UTC)):
    print(f"{dt}: {msg}")