Upsert bank account balance

curl --request PUT \
  --url https://api.light.inc/v1/bank-accounts/{bankAccountId}/balance \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json;charset=UTF-8' \
  --data '
{
  "balance": 123,
  "balanceAt": "2023-11-07T05:31:56Z"
}
'

{
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "bankAccountId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "balanceAt": "2023-11-07T05:31:56Z",
  "balance": 123
}