aws-imagebuilder/CfnImagePipeline: Add ```schedule.timezone``` parameter

### Describe the feature

AWS Image Builder Pipeline now allows you to set a time zone which is used when evaluating the cron expression. This document here shows the update:
https://docs.aws.amazon.com/imagebuilder/latest/APIReference/API_Schedule.html

Affected resources:
- [CfnImagePipeline.ScheduleProperty](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_imagebuilder.CfnImagePipeline.ScheduleProperty.html)

### Use Case

For timezones such as Europe/Berlin, if I want the image pipeline to be consistent all year around I need to manually update this field in the console.

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.135.0

### Environment details (OS name and version, etc.)

Amazon Linux release 2 (Karoo)

Start with the CfnImagePipeline.ScheduleProperty entry point and compare its available fields with the AWS Image Builder Schedule API documentation linked in the issue. Add support for schedule.timezone and verify that the property is exposed for CfnImagePipeline; done means users can configure the timezone without manual console changes.

Written by the indexing model from the issue text.