There is an untranslatable part in dashboard: PluginInfo
"Name" of plugins and their "Description" (which are showed on
Plugins page of dashboard) are not translatable.
$PluginInfo['embedvanilla'] = array( 'Name' => '<Embed> Vanilla', 'Description' => "This plugin is deprecated and no longer supported. Use 'Forum Settings' > 'Embed Forum' instead.", 'Version' => '1.0.10',