False positive unused import of inline given needed by derives

[aartigao]

I've checked other opened issues and it doesn't seem there's one like this (if that's the case, sorry and please close this).

Also I'm not sure since when the issue appears because we have excluded the unused import warnings in our projects. The minimizer, though, I tried with 3.7.1-RC1 and 3.nightly.

Compiler version

3.nightly

Minimized code

//> using scala 3.nightly
//> using dep com.github.plokhotnyuk.jsoniter-scala::jsoniter-scala-core:2.36.0
//> using dep io.github.kitlangton::neotype-jsoniter:0.3.24
//> using options -Wunused:imports

import com.github.plokhotnyuk.jsoniter_scala.core.*
import com.github.plokhotnyuk.jsoniter_scala.macros.*
import neotype.*
import neotype.interop.jsoniter.given

type Bar = Bar.Type
object Bar extends Newtype[Long]

case class Foo(bar: Bar, bars: List[Bar]) derives ConfiguredJsonValueCodec

object JsonExample:

  def main(args: Array[String]): Unit =
    val foo = Foo(Bar(42), List(Bar(1), Bar(2)))
    val jsonString = writeToString(foo)
    println(s"Serialized JSON: $jsonString")

    val parsedFoo = readFromString[Foo](jsonString)
    println(s"Deserialized object: $parsedFoo")

Output

[warn] ./issue.sc:9:33
[warn] unused import
[warn] import neotype.interop.jsoniter.given
[warn]   

Expectation

No warn is emitted as this import is needed by Jsoniter derives.

The import, when removed as suggested by the compiler, makes the compilation fail:

[error] ./issue.sc:14:51
[error] No implicit 'com.github.plokhotnyuk.jsoniter_scala.core.JsonValueCodec[_ >: scala.Nothing <: scala.Any]' defined for 'issue$_.this.Bar.Type'.
[error] case class Foo(bar: Bar, bars: List[Bar]) derives ConfiguredJsonValueCodec
[error]      

[som-snytt]

The imported symbol is inline given, but recursing into Inlined was reverted and still needs to be addressed.

This is just to show the inlined newtypeCodec under -Yplain-printer.

Inlined(Thicket(List()), List(),
  Inlined(Ident(JsonCodecMaker$),
    List(),
    Block(
      List(
        Apply(
          Select(
            Inlined(Thicket(List()),
              List(), Ident(x)),
          addOne),
        List(
          Inlined(Thicket(List()),
            List(),
            Inlined(
              Ident(JsonCodecMaker$),
              List(),
              Apply(
                Select(
                  Inlined(
                    Thicket(List()),
                    List(),
                    Inlined(
                      Apply(
                        TypeApply(
                          Ident(
                            newtypeCodec
                            ),
                        List(TypeTree(),
                          TypeTree())),
                        List(
                        NamedArg(
                          newType,