\Drupal\Core\Asset\LibraryDiscoveryParser should use FileCache to cache the parsed YAML

@smustgrave I've added a test - it's not hard to add something small to a unit test for this.

For the given code in test_script.php, Standard profile installed, on PHP 8.2 and APCu installed and enabled on CLI:

use Drupal\Component\Utility\Timer;
$modules = array_keys(\Drupal::getContainer()->getParameter('container.modules'));

foreach($modules as $module) {
  \Drupal::service('library.discovery.parser')->buildByExtension($module);
}


for ($i = 0; $i < 10; $i++) {
  drupal_flush_all_caches();
  Timer::start('library.discovery.parser');
  foreach($modules as $module) {
    \Drupal::service('library.discovery.parser')->buildByExtension($module);
  }
  Timer::stop('library.discovery.parser');
}

$time = Timer::read('library.discovery.parser');
print "Library parsing completed in {$time}ms\n";

With MR using Symfony YAML

$ vendor/bin/drush scr test_script.php
Library parsing completed in 63.54ms

Without patch using Symfony YAML

$ vendor/bin/drush scr test_script.php
Library parsing completed in 117.06ms

Without patch and with PECL YAML installed

$ vendor/bin/drush scr test_script.php
Library parsing completed in 75.47ms