[Gradle, Test] Bump coroutines and serialization libraries version...

for MPP test. As they were way too old and no longer compatible with
MPP plugin because of the experimental publication model that were used
in earlier versions.

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/HierarchicalMppIT.kt

@@ -871,8 +871,8 @@ class HierarchicalMppIT : KGPBaseTest() {
                 """
                 ${"\n"}
                 dependencies {
-                    "jvmAndJsMainImplementation"("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.4.2")
-                    "jvmAndJsMainCompileOnly"("org.jetbrains.kotlinx:kotlinx-serialization-json:1.0.1")
+                    "jvmAndJsMainImplementation"("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
+                    "jvmAndJsMainCompileOnly"("org.jetbrains.kotlinx:kotlinx-serialization-json:1.4.1")
                 }
             """.trimIndent()
             )