fix generic_includes for 24.1 (#8192)

tools/generic_includes.php missed the #8074 refactoring boat in 24.1 where all Database::singleton have been replaced by NDB_Factory::singleton()->database()

This fixes the generic_includes.php file to use the new way of loading the DB object for branch 24.1-release.

tools/generic_includes.php

@@ -23,7 +23,7 @@
 $client     = new NDB_Client();
 $client->makeCommandLine();
 $client->initialize($configFile);
-$DB            = Database::singleton();
+$DB            = NDB_Factory::singleton()->database();
 $config        = NDB_Config::singleton();
 $lorisInstance = new \LORIS\LorisInstance(
     $DB,