Remove unused shutil import

Signed-off-by: Ibrahim Sani <Ibrahim.Sani@dreamworks.com>

Author: sanikache

src/rez/tests/test_package_cache.py

@@ -11,7 +11,6 @@
 import time
 import subprocess
 import tempfile
-import shutil
 from unittest.mock import patch
 
 from rez.tests.util import TestBase, TempdirMixin, restore_os_environ, \