[AWS::Glue::Crawler] - [BUG] - unable to remove schedule from existing crawler

### Name of the resource

AWS::Glue::Crawler

### Resource Name

_No response_

### Issue Description

I'm using AWS CDK to deploy my CloudFormation stacks. I experienced an issue when deploying an AWS Crawler with a schedule. Redeploying it with the schedule set to `None` or removing this line updates the AWS::Glue::Crawler resource in CloudFormation, but it doesn't remove the Schedule settings. It looks like once the schedule is set, we cannot simply remove it from CloudFormation by removing the schedule property.

### Expected Behavior

Removing schedule erases existing rules and makes it "run on demand".

### Observed Behavior

Removing schedule leaves the previous configuration.

### Test Cases

Test Case 1:
Deploy an AWS Crawler with a schedule expression such as "cron(20-50/10 0 * * ? *)", then redeploy it by removing the schedule expression. Although the CloudFormation stack will reflect the update, the previous schedule setting will still appear on the Crawler page.

Test Case 2:
Deploy an AWS Crawler with a schedule expression like "cron(20-50/10 0 * * ? *)", then redeploy it with the schedule expression set to an empty string (""). The CloudFormation stack will update accordingly, and the Crawler page will display the schedule as "On Demand."

### Other Details

I have already reported this issue to the AWS CDK team, who directed me here.
https://github.com/aws/aws-cdk/issues/33194