Fallback to publishing with coordinates inferred from publication

In Gradle < 4.7, there's no `ComponentWithCoordinates` interface, and we
need to make sure that none of our classes implementing this interface
are loaded with older Gradle versions.

Instead of that interface, we can rely on Gradle's metadata generation
heuristic that takes Maven coordinates for the variants from the
corresponding publications.

libraries/tools/kotlin-gradle-plugin-api/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTarget.kt

@@ -9,10 +9,10 @@ import org.gradle.api.Named
 import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.Project
 import org.gradle.api.attributes.HasAttributes
-import org.gradle.api.component.ComponentWithCoordinates
+import org.gradle.api.component.SoftwareComponent
 import org.gradle.api.internal.component.UsageContext
 
-interface KotlinTargetComponent : ComponentWithCoordinates {
+interface KotlinTargetComponent : SoftwareComponent {
     val target: KotlinTarget
     val publishable: Boolean
 }