Clean up empty tempdirs

[sgnn7]

Summary

While the temp files are cleaned on exit of summon, the parent folder seems to not be part of that auto-clean. This folder contains no sensitive info but it allows for junk empty folders to build up on the system over time.

Steps to Reproduce

• Use !file for a variable
• Run summon

Expected Results

• No empty folders should be left behind

Actual Results (including error logs, if applicable)

• Empty folders are left behind