Cast to int for sorting cereals by calories

Summary: Fix https://github.com/dagster-io/dagster/issues/3240 pointed out by Nate Loker on slack

Test Plan: Execute the pipeline and the most caloric cereal is Mueslix Crispy Blend and the least caloric cereal is All-Bran with Extra Fiber

Reviewers: yuhan

Reviewed By: yuhan

Differential Revision: https://dagster.phacility.com/D5965