Support Scala 3.4 type wildcards

[saeltz]

ScalaPB works just fine up to Scala 3.3.3. Yesterday, I was hunting down a bug in Chimney (scalalandio/chimney#479) and wanted to check if it still exists in Scala 3.4.

After updating my branch to Scala 3.4 compiling the tests started failing because some protos are compiled into Scala as well. Scala 3.4 deprecated the underscore syntax for type wildcards (scala/scala3#18813). With fatal warnings enabled, one gets the warnings below:

[error] -- Error: /teleproto/target/scala-3.4.0/src_managed/test/scalapb/io/moia/migration/migration/V3.scala:71:106 
[error] 71 |  def enumCompanionForFieldNumber(__fieldNumber: _root_.scala.Int): _root_.scalapb.GeneratedEnumCompanion[_] = throw new MatchError(__fieldNumber)
[error]    |                                                                                                          ^
[error]    |`_` is deprecated for wildcard arguments of types: use `?` instead
[error]    |This construct can be rewritten automatically under -rewrite -source 3.4-migration.

The rewrite isn't an option here since we're talking about target files.

Do you have plans to fix this issue? I don't fell comfortable disabling fatal warnings.

[thesamet]

Please search for scala3_sources at https://scalapb.github.io/docs/customizations/ - the option is available as a generator parameter or package option.

[saeltz]

Thanks! I totally missed that configuration option. Solved it via scalapb.gen(scala3Sources = true).