aws-lambda: rewrite handler name for provided.al2

### Describe the feature

If a Lambda function is using the provided.al2 runtime, and has specified a handler other than "bootstrap", CDK should rename the handler file while creating the zip, unless there is also a file named "bootstrap".

It is acceptable but undesirable if an additional flag is needed to enable this behavior.

### Use Case

If a repository houses multiple Go lambdas, naming all the binaries "bootstrap" as the provided.al2 requires is non-trivial. It would be better if CDK could just fix things automatically to work around the runtime's restriction.

### 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

2.85.0

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

Alpine 3.18

The issue names no files or tests. Start by tracing CDK's Lambda zip creation for the provided.al2 runtime and its handler/bootstrap decision; done means a non-bootstrap handler is renamed unless a bootstrap file already exists, with coverage for both cases.

Written by the indexing model from the issue text.