remove unused imports

src/osa/paths.py

@@ -7,11 +7,9 @@
 from typing import List
 import subprocess
 import time
-import os
 
 import lstchain
 from astropy.table import Table
-from astropy import units as u
 from lstchain.onsite import (find_systematics_correction_file,
                              find_time_calibration_file,
                              find_filter_wheels)