Distributions pull in JavaFx `-win` artefacts even on macOS

If I run
```bash
./gradlew assemble
```
on macOS then I find  that `logviewer-app/build/distributions/logviewer-app-0.2.0.tar` contains JavaFX artefacts for both macOS and Windows, i.e. `javafx-base-20-win.jar` and others are included unnecessarily.

I noticed this when using `./gradlew copyDependencies` with an extension that had `qupath-fx-gui` as an implementation dependency.