fix: replace passthru with echo

[wilmardo]

passthru is disabled in most security oriented PHP setups since it allows shell access.

I replaced it with native PHP echo and locally my terminal gets cleared perfectly, what was the reason to do this with echo?

[wilmardo]

Hmm the CI failures seem unrelated to my changes:

There were 2 errors:

1) Spatie\PhpUnitWatcher\Test\WatcherFactoryTest::setting_notification_preserves_other_options
Error: Call to undefined method Symfony\Component\Finder\Finder::ignoreVCSIgnored()

/home/runner/work/phpunit-watcher/phpunit-watcher/src/WatcherFactory.php:24
/home/runner/work/phpunit-watcher/phpunit-watcher/tests/WatcherFactoryTest.php:27

2) Spatie\PhpUnitWatcher\Test\WatcherFactoryTest::setting_directories_preserves_other_options
Error: Call to undefined method Symfony\Component\Finder\Finder::ignoreVCSIgnored()

/home/runner/work/phpunit-watcher/phpunit-watcher/src/WatcherFactory.php:24
/home/runner/work/phpunit-watcher/phpunit-watcher/tests/WatcherFactoryTest.php:44

@freekmurze Are these known errors?

[freekmurze]

Thanks, I'll fix the tests myself