remove usage of "@vercel/request-context"

packages/next/src/server/after/builtin-request-context.ts

@@ -4,23 +4,15 @@ export function getBuiltinRequestContext():
   | BuiltinRequestContextValue
   | undefined {
   const _globalThis = globalThis as GlobalThisWithRequestContext
-  const ctx =
-    _globalThis[NEXT_REQUEST_CONTEXT_SYMBOL] ??
-    _globalThis[VERCEL_REQUEST_CONTEXT_SYMBOL]
+  const ctx = _globalThis[NEXT_REQUEST_CONTEXT_SYMBOL]
   return ctx?.get()
 }
 
 /** This should be considered unstable until `unstable_after` is stablized. */
 const NEXT_REQUEST_CONTEXT_SYMBOL = Symbol.for('@next/request-context')
 
-// TODO(after): this is a temporary workaround.
-// Remove this when vercel builder is updated to provide '@next/request-context'.
-const VERCEL_REQUEST_CONTEXT_SYMBOL = Symbol.for('@vercel/request-context')
-
 type GlobalThisWithRequestContext = typeof globalThis & {
   [NEXT_REQUEST_CONTEXT_SYMBOL]?: BuiltinRequestContext
-  /** @deprecated */
-  [VERCEL_REQUEST_CONTEXT_SYMBOL]?: BuiltinRequestContext
 }
 
 /** A request context provided by the platform.