fix: functions that return promises must be async (#12105)

* fix: Functions that return promises must be async

* fix: Returning an awaited promise is required in this context

Author: thomaslindstrom

packages/next-auth/src/utils/logger.ts

@@ -95,7 +95,7 @@ export function proxyLogger(
 
     const clientLogger: Record<string, unknown> = {}
     for (const level in logger) {
-      clientLogger[level] = (code: string, metadata: Error) => {
+      clientLogger[level] = async (code: string, metadata: Error) => {
         _logger[level](code, metadata) // Logs to console
 
         if (level === "error") {
@@ -107,7 +107,7 @@ export function proxyLogger(
         if (navigator.sendBeacon) {
           return navigator.sendBeacon(url, body)
         }
-        return fetch(url, { method: "POST", body, keepalive: true })
+        return await fetch(url, { method: "POST", body, keepalive: true })
       }
     }
     return clientLogger as unknown as LoggerInstance