Update default session limits

curl --request PATCH \
  --url https://api.pingnetwork.io/customer/v2/customer/limits/session \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "downloaded_bytes": 10737418240,
  "uploaded_bytes": 5368709120,
  "download_speed": 31457280,
  "upload_speed": 20971520
}'

{
  "id": "sl_123456789",
  "created_at": "2025-02-28T14:30:00.000Z",
  "updated_at": "2025-02-28T14:30:00.000Z",
  "downloaded_bytes": 10737418240,
  "uploaded_bytes": 5368709120,
  "download_speed": 31457280,
  "upload_speed": 20971520
}