$depth variable is not used, hence getPrevious method could end up in infinite loop

[AidasK]

Monolog version 3.1.0

https://github.com/Seldaek/monolog/blob/main/src/Monolog/Formatter/LineFormatter.php#L153

$depth variable is not used, hence getPrevious method could end up in infinite loop:

            do {
                $str .= "\n[previous exception] " . $this->formatException($previous);
            } while ($previous = $previous->getPrevious());

This could be changed to:

            do {
                if ($depth++ > $this->maxNormalizeDepth) {
                    $str .= 'Over ' . $this->maxNormalizeDepth . ' levels deep, aborting normalization';
                    break;
                }
                $str .= "\n[previous exception] " . $this->formatException($previous);
            } while (($previous = $previous->getPrevious()));