Add cache:warm CLI command

Google suggests something like below which seems simple enough. I would personally leave it for Contrib or a followup, but I'll change it if anyone really wants.

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Process\Process;

class ParallelTasksCommand extends Command
{
    protected static $defaultName = 'app:run-parallel';

    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        // Define your background processes
        $processes = [
            new Process(['php', 'bin/console', 'app:task-one']),
            new Process(['php', 'bin/console', 'app:task-two']),
        ];

        // Launch all processes asynchronously
        foreach ($processes as $process) {
            $process->start();
        }

        // Wait for all of them to finish (blocking block)
        foreach ($processes as $process) {
            while ($process->isRunning()) {
                // Optional: Read real-time output or sleep to save CPU cycles
                usleep(100000); 
            }
        }

        $output->writeln('All parallel tasks completed.');
        return Command::SUCCESS;
    }
}

Oh, that approach only works if each process runs a CLI command like dr php:eval "FieldDfinintion:warm()" and so on. We don't have a php:eval command yet.