Migrate legacy attachment discriminator class values to modern format, so that we can make the discriminator map unique and fix a deprecation with doctrine

migrations/Version20250222165240.php

@@ -0,0 +1,31 @@
+<?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 Version20250222165240 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Migrate the old attachment class discriminator values from legacy Part-DB to the modern format, so that there is just one unified value';
+    }
+
+    public function up(Schema $schema): void
+    {
+        //Change the old discriminator values to the new ones
+        $this->addSql('UPDATE attachments SET class_name = "Part" WHERE class_name = "PartDB\Part"');
+        $this->addSql('UPDATE attachments SET class_name = "Device" WHERE class_name = "PartDB\Device"');
+    }
+
+    public function down(Schema $schema): void
+    {
+        //No down required, as the new format can also be read by older Part-DB version
+    }
+}