Clean-up some warnings

- kotlin.mpp.enableGranularSourceSetsMetadata=true has no longer effect
- remove redundant opt-in

Author: ilya-g

core/build.gradle.kts

@@ -93,13 +93,12 @@ kotlin {
     sourceSets.all {
         val suffixIndex = name.indexOfLast { it.isUpperCase() }
         val targetName = name.substring(0, suffixIndex)
-        val suffix = name.substring(suffixIndex).toLowerCase(Locale.ROOT).takeIf { it != "main" }
+        val suffix = name.substring(suffixIndex).lowercase().takeIf { it != "main" }
 //        println("SOURCE_SET: $name")
         kotlin.srcDir("$targetName/${suffix ?: "src"}")
         resources.srcDir("$targetName/${suffix?.let { it + "Resources" } ?: "resources"}")
         languageSettings {
             //            progressiveMode = true
-            optIn("kotlin.Experimental")
         }
     }
 

gradle.properties

@@ -13,7 +13,6 @@ java.mainToolchainVersion=8
 java.modularToolchainVersion=11
 
 kotlin.mpp.stability.nowarn=true
-kotlin.mpp.enableGranularSourceSetsMetadata=true
 kotlin.mpp.enableCompatibilityMetadataVariant=true
 kotlin.js.compiler=both
 kotlin.native.ignoreIncorrectDependencies=true