feat(channel): deprecate is_nsfw method in CategoryChannel

Author: Lumabots

discord/channel.py

@@ -3067,6 +3067,12 @@ async def create_forum_channel(self, name: str, **options: Any) -> ForumChannel:
         """
         return await self.guild.create_forum_channel(name, category=self, **options)
 
+    @utils.deprecated(since=2.7, removed=3.0)
+    def is_nsfw(self) -> bool:
+        return False
+
+    # TODO: Remove in 3.0
+
 
 DMC = TypeVar("DMC", bound="DMChannel")