MINOR: Simplify Gradle upgrade

Today, we have to change multiple files when upgrading Gradle:

- gradle/dependencies.gradle
- gradle/wrapper/gradle-wrapper.properties
- gradlew

By using $gradle.gradleVersion, the next Gradle upgrade PR would
only require a version change in gradle-wrapper.properties.

Signed-off-by: Federico Valeri <[email protected]>

Author: fvaleri

build.gradle

@@ -44,7 +44,6 @@ plugins {
 }
 
 ext {
-  gradleVersion = versions.gradle
   minClientJavaVersion = 11
   minNonClientJavaVersion = 17
   modulesNeedingJava11 = [":clients", ":generator", ":streams", ":streams:test-utils", ":streams-scala", ":test-common:test-common-util"]
@@ -251,7 +250,6 @@ static def projectToJUnitXmlPath(project) {
   return projectNames.join("/")
 }
 
-
 apply from: file('wrapper.gradle')
 
 if (repo != null) {
@@ -296,7 +294,7 @@ if (repo != null) {
 } else {
   rat.enabled = false
 }
-println("Starting build with version $version (commit id ${commitId == null ? "null" : commitId.take(8)}) using Gradle $gradleVersion, Java ${JavaVersion.current()} and Scala ${versions.scala}")
+println("Starting build with version $version (commit id ${commitId == null ? "null" : commitId.take(8)}) using Gradle $gradle.gradleVersion, Java ${JavaVersion.current()} and Scala ${versions.scala}")
 println("Build properties: ignoreFailures=$userIgnoreFailures, maxParallelForks=$maxTestForks, maxScalacThreads=$maxScalacThreads, maxTestRetries=$userMaxTestRetries")
 
 subprojects {

gradle/dependencies.gradle

@@ -59,7 +59,6 @@ versions += [
   checkstyle: project.hasProperty('checkstyleVersion') ? checkstyleVersion : "10.20.2",
   commonsValidator: "1.9.0",
   classgraph: "4.8.173",
-  gradle: "8.14",
   grgit: "4.1.1",
   httpclient: "4.5.14",
   jackson: "2.16.2",

wrapper.gradle

@@ -23,21 +23,20 @@
 // and not the version installed on the machine running the task.
 // Read more about the wrapper here: https://docs.gradle.org/current/userguide/gradle_wrapper.html
 wrapper {
-    gradleVersion = project.gradleVersion
     distributionType = Wrapper.DistributionType.ALL
 }
 
 // Custom task to inject support for downloading the gradle wrapper jar if it doesn't exist.
 // This allows us to avoid checking in the jar to our repository.
 // Additionally adds a license header to the wrapper while editing the file contents.
-task bootstrapWrapper() {
+tasks.register('bootstrapWrapper') {
     // In the doLast block so this runs when the task is called and not during project configuration.
     doLast {
         def wrapperBasePath = "\$APP_HOME/gradle/wrapper"
         def wrapperJarPath = wrapperBasePath + "/gradle-wrapper.jar"
 
         // Add a trailing zero to the version if needed.
-        def fullVersion = project.gradleVersion.count(".") == 1 ? "${project.gradleVersion}.0" : versions.gradle
+        def fullVersion = $gradle.gradleVersion.count(".") == 1 ? "$gradle.gradleVersion.0" : versions.gradle
         // Leverages the wrapper jar checked into the gradle project on github because the jar isn't
         // available elsewhere. Using raw.githubusercontent.com instead of github.com because
         // github.com servers deprecated TLSv1/TLSv1.1 support some time ago, so older versions