Upgrade to Gradle 8.2.1

Closes gh-2388

buildSrc/src/main/groovy/io/spring/gradle/convention/DocsPlugin.groovy

@@ -25,7 +25,7 @@ public class DocsPlugin implements Plugin<Project> {
 			group = 'Distribution'
 			archiveBaseName = project.rootProject.name
 			archiveClassifier = 'docs'
-			description = "Builds -${classifier} archive containing all " +
+			description = "Builds -${archiveClassifier} archive containing all " +
 				"Docs for deployment at docs.spring.io"
 
 			from(project.tasks.api.outputs) {

buildSrc/src/main/groovy/io/spring/gradle/convention/SpringModulePlugin.groovy

@@ -18,7 +18,6 @@ package io.spring.gradle.convention;
 
 import org.gradle.api.Project
 import org.gradle.api.plugins.JavaLibraryPlugin;
-import org.gradle.api.plugins.MavenPlugin;
 import org.gradle.api.plugins.PluginManager
 import org.springframework.gradle.maven.SpringMavenPlugin;
 

buildSrc/src/main/groovy/io/spring/gradle/convention/SpringSampleWarPlugin.groovy

@@ -38,7 +38,6 @@ public class SpringSampleWarPlugin extends SpringSamplePlugin {
         project.gretty {
             servletContainer = 'tomcat10'
             contextPath = '/'
-            fileLogEnabled = false
         }
 
         Task prepareAppServerForIntegrationTests = project.tasks.create('prepareAppServerForIntegrationTests') {

buildSrc/src/main/groovy/io/spring/gradle/convention/TestsConfigurationPlugin.groovy

@@ -44,7 +44,7 @@ public class TestsConfigurationPlugin implements Plugin<Project> {
 		}
 
 		project.tasks.create('testJar', Jar) {
-			classifier = 'test'
+			archiveClassifier = 'test'
 			from project.sourceSets.test.output
 		}
 

buildSrc/src/test/resources/samples/showcase/samples/sgbcs-sample-war/build.gradle

@@ -1,5 +1,5 @@
 plugins {
-    id "org.gretty" version "4.0.0"
+    id "org.gretty" version "4.1.0"
     id "io.spring.convention.spring-sample-war"
 }