[core] Unexpected system exit instead of objects_valid crash on exception (ray-project#57247)

Signed-off-by: dayshah <dhyey2019@gmail.com>

Author: dayshah

python/ray/_raylet.pyx

@@ -2462,6 +2462,10 @@ cdef CRayStatus task_execution_handler(
                 if hasattr(e, "unexpected_error_traceback"):
                     msg += (f" {e.unexpected_error_traceback}")
                 return CRayStatus.UnexpectedSystemExit(msg)
+        except Exception as e:
+            msg = "Unexpected exception raised in task execution handler: {}".format(e)
+            logger.error(msg)
+            return CRayStatus.UnexpectedSystemExit(msg)
 
     return CRayStatus.OK()