Error in IntelliJ about Multiple 'scala3-library*.jar' files when using scala 3.x and scalajs

[malcolmredheron]

When I use GenIdea in a mill/scalajs project and then build in intellij, it works fine if build.sc uses scala 2.13.14 but for every version of scala 3 that I have tried IJ gives me errors of the form scala: Multiple 'scala3-library*.jar' files (scala3-library_3-3.3.1.jar, scala3-library_sjs1_3-3.3.1.jar) in Scala compiler classpath in Scala SDK scala-SDK-3.3.1

https://github.com/malcolmredheron/mill-scalajs-experiment contains code and exact steps that demonstrate the problem. This happens for me with mill 0.11.8, 0.11.10, 0.11.11 and 0.11.11-1-066ea7, which is the most recent commit that I could find a build for