Reject discovery application

curl --request POST \
  --url https://api.fluxer.app/v1/admin/discovery/applications/{guild_id}/reject \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "reason": "<string>"
}
'

{
  "guild_id": "<string>",
  "status": "<string>",
  "description": "<string>",
  "category_type": 123,
  "applied_at": "<string>",
  "reviewed_at": "<string>",
  "review_reason": "<string>"
}