We have many AWS Glue jobs and we are only updating the job code, which are scripts stored in S3. The problem is CloudFormation couldn't tell when and when not to update our Glue jobs because all CloudFormation template parameters remain the same after script changes, even the script location is pointing to the same S3 object.
You can use the CloudFormation package command. This enables you to reference local files in your git repository as scripts for Glue Jobs. Every time before you deploy to CloudFormation you just run the package command.