Fix guild.chunk() not working on evicted guilds

If you're trying to chunk a guild that the bot is not in, 
it'll just hang on the chunk coro forever. It's weird, I know.

discord/guild.py

@@ -2223,7 +2223,8 @@ class Guild(Hashable):
         if not self._state._intents.members:
             raise ClientException('Intents.members must be enabled to use this.')
 
-        return await self._state.chunk_guild(self, cache=cache)
+        if not self._state.is_guild_evicted(self):
+            return await self._state.chunk_guild(self, cache=cache)
 
     async def query_members(self, query=None, *, limit=5, user_ids=None, presences=False, cache=True):
         """|coro|

discord/state.py

@@ -827,6 +827,9 @@ class ConnectionState:
 
         return self._add_guild_from_data(data)
 
+    def is_guild_evicted(self, guild) -> bool:
+        return guild.id not in self._guilds
+
     async def chunk_guild(self, guild, *, wait=True, cache=None):
         cache = cache or self.member_cache_flags.joined
         request = self._chunk_requests.get(guild.id)