SpringBoot gradle插件抱怨“未解决的参考：providerRuntime”

Question

我正在关注最新的SpringBoot gradle plugin reference，以便设置可以构建uberjar的SpringBoot项目。

下面是build.gradle.kts的全部内容：

plugins {
    java
    application
    id("org.springframework.boot") version "2.2.1.RELEASE"
    id("io.spring.dependency-management") version "1.0.8.RELEASE"
}

repositories {
    jcenter()
}

dependencies {
    implementation("org.springframework.boot:spring-boot-starter-web")
    providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")
    testImplementation("org.testng:testng:6.14.3")
}

application {
    // Define the main class for the application.
    mainClassName = "com.demo.App"
}

val test by tasks.getting(Test::class) {
    // Use TestNG for unit tests
    useTestNG()
}

dependencyManagement {
    imports {
        mavenBom(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)
    }
}

不幸的是，当我运行gradle命令时，出现以下错误：

> Configure project :
e: /Users/xux/Documents/toys/web/build.gradle.kts:15:5: Unresolved reference: providedRuntime

FAILURE: Build failed with an exception.

* Where:
Build file '/Users/xux/Documents/toys/web/build.gradle.kts' line: 15

* What went wrong:
Script compilation error:

  Line 15:     providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")
               ^ Unresolved reference: providedRuntime

1 error

我正在使用Java 1.8.0_201，Gradle 6.0，Kotlin 1.3.50，Mac OS X 10.15.1 x86_64。