fix(moderation): fixed allowedmention setting in mute command

moderation/moderation.py

@@ -179,7 +179,7 @@ class Moderation(commands.Cog):
     async def mute(self, ctx: commands.Context, target: discord.Member, duration: str, *, reason: str):
         """Mute a user."""
         if target.is_timed_out() is True:
-            await ctx.send(f"{target.mention} is already muted!", allowed_mentions=None)
+            await ctx.send(f"{target.mention} is already muted!", allowed_mentions=discord.AllowedMentions(users=False))
             return
         try:
             parsed_time = parse(sval=duration, as_timedelta=True, raise_exception=True)