Mappig of OpenTelemetry SeverityNumber to PsrLogLevel. @see: https://github.com/open-telemetry/opentelemetry-specification/blob/v1.7…
public const SEVERITY_NUMBER = [ PsrLogLevel::DEBUG => 5, PsrLogLevel::INFO => 9, PsrLogLevel::NOTICE => 10, PsrLogLevel::WARNING => 13, PsrLogLevel::ERROR => 17, PsrLogLevel::CRITICAL => 18, PsrLogLevel::ALERT => 21, PsrLogLevel::EMERGENCY => 22, ];