(aws-backup): support BackupPlanRule.schedule_expression_timezone

[rtandy]

Describe the feature

CloudFormation added ScheduleExpressionTimezone on AWS::Backup::BackupPlan BackupRuleResourceType, and it was automatically picked up on CfnBackupPlan.BackupRuleResourceTypeProperty. Please add it to BackupPlanRule.

CFN: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-backup-backupplan-backupruleresourcetype.html#cfn-backup-backupplan-backupruleresourcetype-scheduleexpressiontimezone

L1: https://docs.aws.amazon.com/cdk/api/v2/python/aws_cdk.aws_backup/CfnBackupPlan.html#backupruleresourcetypeproperty

L2: https://docs.aws.amazon.com/cdk/api/v2/python/aws_cdk.aws_backup/BackupPlanRule.html

Could potentially also be solved by changing BackupPlanRule.schedule_expression to accept aws_scheduler.ScheduleExpression (and supporting its timezone parameter) instead of/in addition to aws_events.Schedule. See also #21181.

Thank you!

Use Case

I would like to schedule my backups to run at a consistent local time with automatic DST adjustment.

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

AWS CDK Library version (aws-cdk-lib)

2.176.0

AWS CDK CLI version

2.1016.1 (build 6de56b2)

Environment details (OS name and version, etc.)

macOS 15.5 (24F74)