feat(codepipeline): executionMode property for Pipeline (#29148)

### Issue # (if applicable)

Closes #29147.

### Reason for this change

We would be good to add a new parameter for execution mode.

see:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-codepipeline-pipeline.html#cfn-codepipeline-pipeline-executionmode

https://aws.amazon.com/about-aws/whats-new/2024/02/codepipeline-trigger-filters-execution-modes

### Description of changes

Add an `executionMode` parameter to the `PipelineProps` interface.

### Description of how you validated changes

Both unit and integ tests.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: go-to-k