Explicitly import exit from sys (#2259)

Signed-off-by: WebOfNakedFancies <[email protected]>

flytekit/bin/entrypoint.py

@@ -8,6 +8,7 @@
 import subprocess
 import tempfile
 import traceback as _traceback
+from sys import exit
 from typing import List, Optional
 
 import click as _click