fix: make locale parameter optional in layout props

Author: franz-bendezu

src/app/[locale]/layout.tsx

@@ -16,7 +16,7 @@ export function generateStaticParams() {
 
 type Props = {
   children: React.ReactNode;
-  params: Promise<{ locale: Locale }>;
+  params: Promise<{ locale?: Locale }>;
 };
 
 export async function generateMetadata({ params }: Props): Promise<Metadata> {