Set the default theme to arDominionB5Plugin

Changes the default theme to be the Bootstrap 5 Dominion theme so that
new installs use the BS5 theme.

Author: anvit

lib/arInstall.class.php

@@ -315,7 +315,7 @@ public static function loadData($dispatcher, $formatter)
         $object->name = 'plugins';
         $object->value = serialize([
             'sfDcPlugin',
-            'arDominionPlugin',
+            'arDominionB5Plugin',
             'sfEacPlugin',
             'sfEadPlugin',
             'sfIsaarPlugin',