Drop unnecessary filter on artifacts

[alexarchambault]

Artifacts should already be filtered by coursier.Artifacts (via the default classifiers and artifact types stuff), no need to filter them further

[lefou]

To preserve previous behavior, you should change the resolveFilter default to contain the path.ext == "jar" match, I guess.

[alexarchambault]

Precisely, that's not needed. Coursier already filters artifacts (by default, it keeps these types, which are all fine to be put in a class path). My guess is this filter was necessary when you were using the coursier 1.x API, which didn't filter artifacts as much out-of-the-box.

The PR here should be considered to be a follow-up of #3513

[alexarchambault]

Also, that change is necessary for #3702 and #3703. For #3702, we want klib artifacts to be fetched out-of-the-box, so we must accept *.klib files. For #3703, if users add a fancy type in JavaModule.artifactTypes, we want it to be put in the class path too, without requiring more changes by users.