fix: DB Seeder may use wrong DB connection during testing

The shared migration holds an old DB connection.
If SQLite3 `:memory:` is used, a new DB connection is a connection to a new database.

Author: kenjis

system/Test/DatabaseTestTrait.php

@@ -79,7 +79,7 @@ public function loadDependencies()
             $config          = new Migrations();
             $config->enabled = true;
 
-            $this->migrations = Services::migrations($config, $this->db);
+            $this->migrations = Services::migrations($config, $this->db, false);
             $this->migrations->setSilent(false);
         }