[Gradle, Test] Update `kotlin-js-plugin-project` with sources publication

Sources are published now as gradle variant, so it shouldn't be added
manually to publication.

^KT-36943
diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-plugin-project/build.gradle.kts b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-plugin-project/build.gradle.kts
index b67eb5a..253564e 100644
--- a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-plugin-project/build.gradle.kts
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-plugin-project/build.gradle.kts
@@ -51,7 +51,6 @@
     publications {
         create("default", MavenPublication::class.java) {
             from(components.getByName("kotlin"))
-            artifact(tasks.getByName("kotlinSourcesJar"))
         }
     }
     repositories {