* move setLang() to a root layout

* fix: findLang only returns acceptable languages
* fix: fallback to use header x-lang if we haven't setLang yet
* fix: languageSchema, allow uppercase

Approved-by: Linus Flood

app/[lang]/(live)/(public)/hotelreservation/(confirmation)/booking-confirmation/page.tsx

@@ -1,15 +1,12 @@
 import { getBookingConfirmation } from "@/lib/trpc/memoizedRequests"
 
 import BookingConfirmation from "@/components/HotelReservation/BookingConfirmation"
-import { setLang } from "@/i18n/serverContext"
 
 import type { LangParams, PageArgs } from "@/types/params"
 
 export default async function BookingConfirmationPage({
-  params,
   searchParams,
 }: PageArgs<LangParams, { confirmationNumber: string }>) {
-  setLang(params.lang)
   void getBookingConfirmation(searchParams.confirmationNumber)
   return (
     <BookingConfirmation confirmationNumber={searchParams.confirmationNumber} />