Fix - uses show cli.nativeImage command to generate native image

[lwronski]

Fixes #1972.

I was able to successfully build a native image on Ubuntu for the aarch64 using command:

./mill -i show cli.nativeImage

This fixed this error:

Exception in thread "main" java.lang.NoClassDefFoundError: com.oracle.svm.core.JavaMainWrapper
        at scala.cli.internal.Argv0.get(Argv0.scala:16)
        at scala.cli.ScalaCli$.<clinit>(ScalaCli.scala:28)
        at scala.cli.ScalaCli.main(ScalaCli.scala)