Handle closed DMs in paste uploader

[Copilot]

Fix paste uploader to handle when DMs are closed

• Analyze the code at line 131 in attachment_pastebin_uploader.py
• Add import for discord.Forbidden exception
• Wrap the author.send() call in try/except block
• Continue with returning the link in the original channel when DM fails
• Review the change to ensure it follows the existing pattern in the codebase
• Verify linting passes
• Address review feedback: Use discord.Forbidden instead of importing Forbidden

The fix catches the discord.Forbidden exception when a user has DMs disabled and logs the event at debug level, then continues with the paste upload flow by posting the link in the original channel.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Paste uploader does not catch when dms are closed</issue_title>
<issue_description>We're not catching or responding when a user cannot be DMed when uploading a paste message: we should try/catch the author.send() method.

I don't know what behaviour we should have regarding deleting the paste, continuing with the upload, or what we should do if DMs are closed.

bot/bot/exts/utils/attachment_pastebin_uploader.py

Line 131 in 2640aaa

await message.author.send(content=f"[Click here](<{paste_response.removal}>) to delete your recent paste.")

related to #3422</issue_description>

<agent_instructions>Add a try/except (for the correct exception type) and continue with returning the link in the original channel</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@jb3 The user has already reacted to say they want it uploaded, having the deletion link is a nicety but isn't required, DevOps can still delete pastes or they expire after a period, it's not the end of the world.

• Fixes Paste uploader does not catch when dms are closed #3423

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[jb3]

Instead of specifically importing Forbidden, use discord.Forbidden here.

[Copilot]

Changed to use discord.Forbidden in commit 76d1d7b.

[jb3]

@copilot Please address review feedback.

[Copilot]

@copilot Please address review feedback.

Review feedback addressed in commit 76d1d7b.

[vivekashok1221]

LGTM