[build] Properly mark jvm/awt source sets as optional, respecting the… (#1124)

… 'skiko.awt.enabled' feature flag

skiko/build.gradle.kts

@@ -176,7 +176,7 @@ kotlin {
         implementation(kotlin("test-annotations-common"))
     }
 
-    skikoProjectContext.jvmMainSourceSet.dependencies {
+    skikoProjectContext.jvmMainSourceSet?.dependencies {
         implementation(kotlin("stdlib"))
         implementation(libs.coroutines.core.jvm)
     }
@@ -189,7 +189,7 @@ kotlin {
         implementation(libs.coroutines.android)
     }
 
-    skikoProjectContext.jvmTestSourceSet.dependencies {
+    skikoProjectContext.jvmTestSourceSet?.dependencies {
         implementation(libs.coroutines.test)
         implementation(kotlin("test-junit"))
         implementation(kotlin("test"))

skiko/buildSrc/src/main/kotlin/sourceHierarchy.kt

@@ -3,9 +3,9 @@
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.plugin.KotlinHierarchyTemplate
 
-val SkikoProjectContext.jvmMainSourceSet get() = kotlin.sourceSets.getByName("jvmMain")
+val SkikoProjectContext.jvmMainSourceSet get() = if (project.supportAwt) kotlin.sourceSets.getByName("jvmMain") else null
 
-val SkikoProjectContext.jvmTestSourceSet get() = kotlin.sourceSets.getByName("jvmTest")
+val SkikoProjectContext.jvmTestSourceSet get() = if (project.supportAwt) kotlin.sourceSets.getByName("jvmTest") else null
 
 val SkikoProjectContext.awtMainSourceSet get() = if (project.supportAwt) kotlin.sourceSets.getByName("awtMain") else null