fix(ts): revert session callback type changes (#7136)

Fixes t3-oss/create-t3-app#1328

Author: juliusmarminge

packages/next-auth/src/core/types.ts

@@ -319,7 +319,7 @@ export interface CallbacksOptions<P = Profile, A = Account> {
   session: (
     params:
       | {
-          session: DefaultSession
+          session: Session
           /** Available when {@link SessionOptions.strategy} is set to `"jwt"` */
           token: JWT
           /** Available when {@link SessionOptions.strategy} is set to `"database"`. */