Provide ability to disable graph generation

### Contributor Checklist
- [x] I have read the [Contributing guide](https://github.com/autonomousapps/dependency-analysis-gradle-plugin/blob/main/CONTRIBUTING.asciidoc).
- [x] I have read the [Code of Conduct](https://github.com/autonomousapps/dependency-analysis-gradle-plugin/blob/main/CODE_OF_CONDUCT.md).
- [x] No part of this feature request was created with an LLM/AI.

### Is your feature request related to a problem? Please describe.

In a large project with > 400 modules, running the buildHealth check takes some time. At the same time, it generates around ~1.85 GB worth of graph information.

### Describe the solution you'd like

something like:
```kotlin
dependencyAnalysis {
generateGraphAnalysis.set(false)
}
```

### Describe alternatives you've considered

### Additional context

Start by locating the dependencyAnalysis configuration entry point and the code invoked by the buildHealth check. Trace where graph analysis is generated and identify the existing tests for this configuration or task. Done means setting generateGraphAnalysis to false skips graph generation while buildHealth still works, with coverage for both enabled and disabled behavior.

Written by the indexing model from the issue text.