Provide a test to replicate issue #102

[DavidGregory084]

This is a test to replicate #102 thanks to @keynmol's great example on the ticket

[DavidGregory084]

I've realised now that this -scalajs option is for Scala 3.x only

[DavidGregory084]

Unscoped settings no longer receive the changes applied by this plugin if we are using configuration filters

[DavidGregory084]

The latest commit attempts to resolve the problem by dropping derived settings and switching to configuration filters.

The immediate problem with this was that manipulating unscoped settings no longer worked, e.g. the following manipulation no longer contributed to Compile/tpolecatReleaseModeOptions:

tpolecatReleaseModeOptions ++= {
  ScalacOptions.optimizerOptions("**") +
    ScalacOptions.release("8") +
    ScalacOptions.privateBackendParallelism(8)
}

This prompted me to try appending to tpolecatReleaseModeOptions in the sbtTpolecatSettings, which unfortunately breaks the ordering of options that we got from using ListSet within the plugin:

    tpolecatDevModeOptions ++= ScalacOptions.default,
    tpolecatCiModeOptions ++= tpolecatDevModeOptions.value + ScalacOptions.fatalWarnings,
    tpolecatReleaseModeOptions ++= tpolecatCiModeOptions.value + ScalacOptions.optimizerMethodLocal,

I'm afraid it did not resolve the problem in any case as we still see settings duplication in the modePerConfiguration test in Test/scalacOptions regardless of whether ++= is used in the tpolecat*Options.

[DavidGregory084]

No longer needed due to #126