`findKotlinMagicFunTest` task causes "No such file or directory"

### 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 bug report was created with an LLM/AI.

### (Optional) Build scan link
https://gradle.com/s/gg76cxj37xee2

### Plugin version
3.18.0

### Gradle version
9.7.0

### JDK version
25

### (Optional) Kotlin and Kotlin Gradle Plugin (KGP) version
2.4.10

### (Optional) Android Gradle Plugin (AGP) version
n/a

### (Optional) `reason` output for bugs relating to incorrect advice
n/a

### Describe the bug
Running the `buildHealth` task fails with

```
* What went wrong:
Execution failed for task ':downloader:findKotlinMagicFunTest' (registered by plugin 'com.autonomousapps.dependency-analysis').
> There was a failure while executing work items
> A failure occurred while executing com.autonomousapps.tasks.FindKotlinMagicTask$Action
> /home/sebastian/Development/GitHub/oss-review-toolkit/ort/downloader/build/classes/kotlin/test/org/ossreviewtoolkit/downloader/VcsHostTest$1$8$3.class (No such file or directory)
```

### To Reproduce
Steps to reproduce the behavior:
1. Checkout https://github.com/oss-review-toolkit/ort/tree/plugin-api-compile-only
2. Run `./gradlew --scan buildHealth`

### Expected behavior
No "No such file or directory" error is thrown.

### Additional context
n/a

Reproduce the failure with ./gradlew --scan buildHealth on the specified ORT plugin-api-compile-only checkout, then inspect the FindKotlinMagicTask$Action execution for the :downloader:findKotlinMagicTest task. Done means the buildHealth task completes without a "No such file or directory" error for the reported class path.

Written by the indexing model from the issue text.