sbt-mima for sbt 2.x does not handle `platform` in `mimaPreviousArtifacts`

[WojciechMazur]

Issue spotted in scala-native during migration to sbt 2.x
Mima plugin ignores platform settings specified for the target - it treats all ModuleId as if they were defiend for JVM

Our workaround was to explicitly map cross version so that it matches the platform information is propagated though this channel

platform.value match
    case ScalaNativePlatform => ScalaNativeCrossVersion.scalaNativeMapped(crossVersion.value)
    case _                   => crossVersion.value