Update java up-to-date test project to plugins api.

^KT-45747 In Progress

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/javaUpToDate/build.gradle

@@ -1,21 +1,9 @@
-buildscript {
-    repositories {
-        mavenLocal()
-        mavenCentral()
-    }
-    dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-    }
+plugins {
+    id "java"
+    id "org.jetbrains.kotlin.jvm"
 }
 
-apply plugin: "kotlin"
-apply plugin: "java"
-
 repositories {
     mavenLocal()
     mavenCentral()
 }
-
-dependencies {
-    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-}