Add migration to fix comment for multipass limit column

This was wrong in #2725.

webapp/migrations/Version20241122152658.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20241122152658 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Fix comment for multipass limit field';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE problem CHANGE multipass_limit multipass_limit INT UNSIGNED DEFAULT NULL COMMENT \'Optional limit on the number of rounds; defaults to 1 for traditional problems, 2 for multi-pass problems if not specified.\'');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE problem CHANGE multipass_limit multipass_limit INT UNSIGNED DEFAULT NULL COMMENT \'Optional limit on the number of rounds for multi-pass problems; defaults to 2 if not specified.\'');
+    }
+
+    public function isTransactional(): bool
+    {
+        return false;
+    }
+}