Prevent user from modify the DebuGymLogger's level

[MarcCote]

Right now, if a user does the following

import logging

logger = DebugGymLogger("debug-gym", log_dir="/tmp/logs/")
logger.setLevel(logging.INFO)

all the debugging information won't be saved in the log file (i.e., "/tmp/logs/debug_gym.log").

Suggestion, overwrite the setLevel method to only change the level of the rich_handler responsible to print logging information to stdout.