fix(player): set blank filter if no filters enabled

[ooliver1]

Summary

Set a blank filter if no filters are applied and are updated.

https://canary.discord.com/channels/864563184919773226/1076074968087011409/1076074968087011409

17.02.2023 11:26:46 | INFO | Cattosarus#0463 ran application command "bassboost"
Ignoring exception in command <nextcord.application_command.SlashApplicationCommand object at 0x00000140A183F700>:
Traceback (most recent call last):
  File "C:\Users\Cattosarus\AppData\Local\Programs\Python\Python39\lib\site-packages\nextcord\application_command.py", line 863, in invoke_callback_with_hooks
    await self(interaction, *args, **kwargs)
  File "c:\Users\Cattosarus\Desktop\mafic-bot\cogs\music.py", line 258, in bassboost
    await player.remove_filter("bassboost")
  File "C:\Users\Cattosarus\AppData\Local\Programs\Python\Python39\lib\site-packages\mafic\player.py", line 689, in remove_filter
    await self._update_filters(fast_apply=fast_apply)
  File "C:\Users\Cattosarus\AppData\Local\Programs\Python\Python39\lib\site-packages\mafic\player.py", line 635, in _update_filters
    await self.update(filter=reduce(or_, self._filters.values()))
TypeError: reduce() of empty sequence with no initial value

The above exception was the direct cause of the following exception:

nextcord.errors.ApplicationInvokeError: Command raised an exception: TypeError: reduce() of empty sequence with no initial value

Checklist

• If code changes were made then they have been tested.
• I have run task lint to format code and my changes.
• I have run task pyright and fixed the relevant issues.