There 3 main scenarios that I can think of:
1) Any attached files to a parallel pool will be deleted when the pool goes out of scope and is deleted.
2) Same thing is true for files attached to a particular job.
3) If you want to delete an attached file before the termination of the corresponding pool, you might have write it manually in your code. You might want to keep track of a condition and when that condition is meet, get the attached files name/path and delete it.
You might want to refer to the links given below:
