[KPM] Convert noop implementations from 'object' to 'val'

This is to avoid leaking the extension function defined
inside those objects to the global namespaces.
Using these extensions on the receiver outside the
noop object makes no sense.

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/KotlinFragmentConfigurationDefinition.kt

@@ -51,8 +51,8 @@ internal typealias FragmentRelation = KotlinGradleFragmentConfigurationRelation
 fun interface KotlinGradleFragmentConfigurationRelation {
     fun KotlinGradleFragmentConfigurationContext.setupExtendsFromRelations(configuration: Configuration)
 
-    object None : KotlinGradleFragmentConfigurationRelation {
-        override fun KotlinGradleFragmentConfigurationContext.setupExtendsFromRelations(configuration: Configuration) = Unit
+    companion object {
+        val None = FragmentRelation {}
     }
 }
 
@@ -62,8 +62,8 @@ internal typealias FragmentAttributes<T> = KotlinGradleFragmentConfigurationAttr
 fun interface KotlinGradleFragmentConfigurationAttributes<in T : KotlinGradleFragment> {
     fun AttributeContainer.setAttributes(fragment: T)
 
-    object None : KotlinGradleFragmentConfigurationAttributes<KotlinGradleFragment> {
-        override fun AttributeContainer.setAttributes(fragment: KotlinGradleFragment) = Unit
+    companion object {
+        val None = FragmentAttributes<KotlinGradleFragment> {}
     }
 }
 /* Internal abbreviation */
@@ -84,9 +84,10 @@ fun interface KotlinGradleFragmentConfigurationCapabilities<in T : KotlinGradleF
 
     fun Context.setCapabilities(fragment: T)
 
-    object None : KotlinGradleFragmentConfigurationCapabilities<KotlinGradleFragment> {
-        override fun Context.setCapabilities(fragment: KotlinGradleFragment) = Unit
+    companion object {
+        val None = FragmentCapabilities<KotlinGradleFragment> {}
     }
+
 }
 
 /* Internal abbreviation */
@@ -95,8 +96,8 @@ internal typealias FragmentArtifacts<T> = KotlinGradleFragmentConfigurationArtif
 fun interface KotlinGradleFragmentConfigurationArtifacts<in T : KotlinGradleFragment> {
     fun ConfigurationPublications.addArtifacts(fragment: T)
 
-    object None : KotlinGradleFragmentConfigurationArtifacts<KotlinGradleFragment> {
-        override fun ConfigurationPublications.addArtifacts(fragment: KotlinGradleFragment) = Unit
+    companion object {
+        val None = FragmentArtifacts<KotlinGradleFragment> {}
     }
 }