Add forum filter

pyrogram/filters.py

@@ -513,6 +513,17 @@ async def channel_filter(_, __, m: Message):
 """Filter messages sent in channels."""
 
 
+# endregion
+
+# region forum_filter
+async def forum_filter(_, __, m: Message):
+    return bool(m.chat and m.chat.is_forum)
+
+
+forum = create(forum_filter)
+"""Filter messages sent in forums."""
+
+
 # endregion
 
 # region new_chat_members_filter