* 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-current)/layout.tsx

@@ -12,7 +12,6 @@ import SkipToMainContent from "@/components/SkipToMainContent"
 import RouterTracking from "@/components/TrackingSDK/RouterTracking"
 import { getIntl } from "@/i18n"
 import ServerIntlProvider from "@/i18n/Provider"
-import { setLang } from "@/i18n/serverContext"
 
 import type { Metadata } from "next"
 
@@ -31,7 +30,6 @@ export default async function RootLayout({
 }: React.PropsWithChildren<
   LayoutArgs<LangParams> & { header: React.ReactNode }
 >) {
-  setLang(params.lang)
   const { defaultLocale, locale, messages } = await getIntl()
 
   return (