(cli/core): concurrent asset builds for ILocalBundling.tryBundle()

### Describe the feature

In this PR https://github.com/aws/aws-cdk-cli/pull/983 - were introduced concurrent asset builds for Docker builds, but we need the same for local

comment from previous PR

You're right that --asset-build-concurrency only applies to Docker-based asset builds in the CLI's work graph, not to ILocalBundling.

Deferring local bundling to the work graph is a very appealing idea. However, ILocalBundling.tryBundle() is called synchronously during synthesis inside the CDK app process, which is a completely separate phase from the CLI's work graph execution. This would require changes on both the framework side (aws-cdk-lib) and the CLI side, which is a significant architectural change beyond the scope of this PR.

It might be worth opening a separate feature request issue for that so the maintainers can weigh in on the approach. In the meantime, a note in the documentation clarifying that this flag applies to Docker-based builds only could also help avoid confusion.

### Use Case

I have 1xxx of golang lambdas builded localy - I would like to use the same --asset-build-concurrency 4 flag for these local builds

### 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

v2.1109.0

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

Fedora 44