Merge pull request #48 from pxlrbt/fix/nullable-get-url

fix: `getUrl()` might return null

src/Actions/RegisterUserMenu.php

@@ -44,7 +44,7 @@ protected function getName(string $key, MenuItem $item): ?string
         };
     }
 
-    protected function getUrl(string $key, MenuItem $item): string
+    protected function getUrl(string $key, MenuItem $item): ?string
     {
         return match ($key) {
             'logout' => $item->getUrl() ?? Filament::getLogoutUrl(),