Remove fir:lightTree test on kotlinx.coroutines as it caused problems in IDEA

compiler/fir/lightTree/.gitignore

@@ -1 +0,0 @@
-testData

compiler/fir/lightTree/build.gradle.kts

@@ -1,10 +1,5 @@
-import org.ajoberstar.grgit.Grgit
-
 plugins {
     kotlin("jvm")
-
-    //git plugin
-    id("org.ajoberstar.grgit") version "3.1.1"
 }
 
 group = "org.jetbrains.kotlin.fir"
@@ -97,16 +92,3 @@ val jmhExec by tasks.creating(JavaExec::class) {
     systemProperty("idea.max.intellisense.filesize", 5000 * 1024)
     configurations.plusAssign(project.configurations["compile"])
 }
-
-val deleteGitFolder by tasks.creating(Delete::class) {
-    delete("$testDataPath/.git")
-}
-
-val cloneCoroutines by tasks.creating {
-    val url = "https://github.com/Kotlin/kotlinx.coroutines.git"
-    if (!File(testDataPath).exists()) {
-        Grgit.clone(mapOf("dir" to testDataPath,
-                      "uri" to url)).close()
-    }
-    finalizedBy(tasks["deleteGitFolder"])
-}

compiler/fir/lightTree/tests/org/jetbrains/kotlin/fir/lightTree/benchmark/coroutines/AbstractCoroutinesBenchmark.kt

@@ -1,20 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
- * that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.fir.lightTree.benchmark.coroutines
-
-import org.jetbrains.kotlin.fir.lightTree.benchmark.AbstractBenchmarkForGivenPath
-import org.jetbrains.kotlin.fir.lightTree.benchmark.generators.LightTree2FirGenerator
-import org.jetbrains.kotlin.fir.lightTree.benchmark.generators.Psi2FirGenerator
-import org.jetbrains.kotlin.fir.lightTree.benchmark.generators.TreeGenerator
-
-abstract class AbstractCoroutinesBenchmark :
-    AbstractBenchmarkForGivenPath(System.getProperty("user.dir") + "/compiler/fir/lightTree/testData/coroutines", false)
-
-open class LightTree2FirCoroutinesBenchmark(override val generator: TreeGenerator = LightTree2FirGenerator()) :
-    AbstractCoroutinesBenchmark()
-
-open class Psi2FirCoroutinesBenchmark(override val generator: TreeGenerator = Psi2FirGenerator()) :
-    AbstractCoroutinesBenchmark()