[Gradle, JS] Do not check exit code

Because mocha don't make difference between infrastructure and runtime problems and failing tests
This reverts commit e6d39ce7
https://github.com/mochajs/mocha/issues/4216

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/mocha/KotlinMocha.kt

@@ -92,7 +92,7 @@ class KotlinMocha(override val compilation: KotlinJsCompilation) :
         return TCServiceMessagesTestExecutionSpec(
             forkOptions,
             args,
-            true,
+            false,
             clientSettings
         )
     }