Remove query param that no longer exists on GET /invites/<code>

[Rodentman87]

Fixes #7395, query param was removed a while ago but the docs were never updated.

[Droid00000]

Shouldn't the description for expires_at be updated here as well? https://discord.com/developers/docs/resources/invite#invite-object-invite-structure

[advaith1]

Is the expires_at field still optional? If so, when is it not returned?

[Sacul0457]

Any updates on this? Also, it seems like the expires_at field is also present when an invite is created.
https://discord.com/developers/docs/events/gateway-events#invite-create

{'uses': 0, 'type': 0, 'temporary': False, 'max_uses': 0, 'max_age': 43200,
 'is_nickname_changeable': False, 'inviter': {'...'}, 'guild_id': '1294290832219963563', 
 'expires_at': '2025-08-11T15:51:03+00:00', 'created_at': '2025-08-11T03:51:03.054974+00:00', 
 'code': '...', 'channel_id': '1352514922462052423'}