fix(executor): reset RUNFILES_DIR
This fix solves a situation which RUNFILES_DIR environmental variable is not cleared in the subsequent execution.
Example: When executing a test that is using more than one py_binary rule.
Edited by Chen Hayat
This fix solves a situation which RUNFILES_DIR environmental variable is not cleared in the subsequent execution.
Example: When executing a test that is using more than one py_binary rule.