az containerapp update -n ContainerAppName -g ResourceGroup --min-replicas 0 --max-replicas 0 finishes without throwing any error, however scaling configuration is not updated as max replicas cannot be zero.

$ az version
{
  "azure-cli": "2.37.0",
  "azure-cli-core": "2.37.0",
  "azure-cli-telemetry": "1.0.6",
  "extensions": {
    "containerapp": "0.3.5",
  }
}