* [new-exec] shrink downstream map (#41471)

* shrink downstream map

* shrink last live ops of var

* add comment

* fix bug

* add dependency for send/recv to support pp parallel (#41652)

* [new-exec] clear the scope listener after run (#41947)

* clear the listener after run

* only sync variables in program

* refine code

* fit for lod_tensor_blocking_queue