jsii-pacmak can not pull dependencies from code artifact or any other internal repository

### Describe the feature

If the project has dependencies on a non open source library, e.g a library built and hosted via code artifact there is no way to configure jsii-pacmak to pull dependencies from code artifact or any other internal dependencies.

Note: This is only an issue for Java based projects.

### Use Case

If an organization is building internal JSII projects that depend on another internal JSII project hosted in code artifact, there is no way to pull those dependencies when running
`rpm run package `
command.

### Proposed Solution

There should be a way to merge settings.xml available locally with user.xml generated by JSII.

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.66.1

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

MacOS

Start by locating the jsii-pacmak Java packaging flow and the code that generates user.xml; then compare how a local settings.xml is expected to supply internal repository credentials and dependencies. Done means rpm run package can use the local settings.xml together with the generated user.xml for Java projects, including dependencies hosted in CodeArtifact or another internal repository.

Written by the indexing model from the issue text.