Editing a deferred response to a message containing an attachment doesn't work

[advaith1]

Description
After sending a deferred interaction response, editing it to a message with an attachment or sending a followup with an attachment (which replaces the Thinking message) does not show the attachment.

Untouched code which used to show the attachment properly in a followup now does not show the attachment.

Sending a type 4 response and then sending a followup with an attachment does show the attachment.

Steps to Reproduce

• Send a deferred interaction response
• use Edit Original Interaction Response or send a followup including an attachment

Expected Behavior
the attachment is shown

Current Behavior
it is not; it actually seems to be added but then removed

Screenshots/Videos
Adding an embed that contains an attached image
Gateway logs:

(only one edit is done by the bot, which is adding the embed with the image)

Client and System Information
Client:
Canary 80356 (1890cdf)
Host 1.0.28
Windows 10 64-Bit (10.0.21337)

Sending with discord.js PR discordjs/discord.js#5223

[devsnek]

This will be fixed in the next api deploy