feat(events): add RetryPolicy support for EventBridge rule targets

[VirtueMe]

Summary

• Adds retryPolicy configuration to schedule (eventBus method) and cloudwatchEvent/eventBridge events
• Emits a CloudFormation RetryPolicy on the AWS::Events::Rule target with MaximumEventAgeInSeconds and MaximumRetryAttempts

Closes #575

Example

stateMachines:
  myMachine:
    events:
      - schedule:
          rate: rate(10 minutes)
          retryPolicy:
            maximumEventAgeInSeconds: 3600
            maximumRetryAttempts: 3
      - eventBridge:
          event:
            source:
              - aws.ec2
          retryPolicy:
            maximumEventAgeInSeconds: 7200
            maximumRetryAttempts: 5

Test plan

• Unit tests added for compileCloudWatchEventEvents (cloudwatchEvent + eventBridge)
• Unit tests added for compileScheduledEvents (eventBus method)
• Verified RetryPolicy is absent when retryPolicy is not configured
• Full test suite passes (452 tests)

🤖 Generated with Claude Code

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commit: 0a37a43

[zirkelc]

Please add to README

[VirtueMe]

Added the missing README section documenting retryPolicy for schedule and eventBridge/cloudwatchEvent events, including a TOC entry and example.