Use `jsExecutionFiles` for toolsJS's `js-test-definitions.js` file.
Use `jsExecutionFiles` for toolsJS's `js-test-definitions.js` file.

We used to use a resource generator combined with a `ProvidedJS`
in `jsDependencies`. It is much simpler to directly use
`jsExecutionFiles` with an in-memory virtual JS file instead.

sjrd/scala-js,nicolasstucki/scala-js,scala-js/scala-js,gzm0/scala-js,nicolasstucki/scala-js,SebsLittleHelpers/scala-js,sjrd/scala-js,scala-js/scala-js,sjrd/scala-js,gzm0/scala-js,scala-js/scala-js,SebsLittleHelpers/scala-js