Tweak: read auth providers in-process on the sign-in page, set env earlier (#7023)

src/instrumentation.js

@@ -0,0 +1,7 @@
+import { applyNextAuthEnv } from "utils/env";
+
+export function register() {
+  if (process.env.NEXT_RUNTIME !== "nodejs") return;
+
+  applyNextAuthEnv();
+}