Use "charset" in Attachment.content_type to determine that it's text-based.

Previously, `on_message` used `Attachment.content_type.startswith("text")` for this, but this is false for some text-based files (like json).

Author: swfarnsworth

bot/exts/utils/attachment_pastebin_uploader.py

@@ -79,7 +79,7 @@ async def on_message_delete(self, message: discord.Message) -> None:
     async def on_message(self, message: discord.Message) -> None:
         """Listens for messages containing attachments and offers to upload them to the pastebin."""
         # Check if the message contains an embedded file and is not sent by a bot.
-        if message.author.bot or not any(a.content_type.startswith("text") for a in message.attachments):
+        if message.author.bot or not any("charset" in a.content_type for a in message.attachments):
             return
 
         log.trace(f"Offering to upload attachments for {message.author} in {message.channel}, message {message.id}")