Fix multi-project incremental JS tests are not actually running

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

@@ -24,6 +24,7 @@ class IncrementalCompilationJsMultiProjectIT : BaseIncrementalCompilationMultiPr
             subProject.buildGradle.writeText(buildGradleJs.readText())
             buildGradleJs.deleteExisting()
         }
+        test()
     }
 
     override val additionalLibDependencies: String =