Address the build's own deprecation warnings

Author: wilkinsona

build.gradle

@@ -44,8 +44,10 @@ subprojects { subproject ->
 		subproject.apply plugin: "io.spring.javaformat"
 		subproject.apply plugin: "checkstyle"
 
-		sourceCompatibility = 17
-		targetCompatibility = 17
+		java {
+			sourceCompatibility = 17
+			targetCompatibility = 17
+		}
 
 		configurations {
 			internal {

spring-restdocs-core/build.gradle

@@ -22,7 +22,7 @@ task jmustacheRepackJar(type: Jar) { repackJar ->
 		project.ant {
 			taskdef name: "jarjar", classname: "com.tonicsystems.jarjar.JarJarTask",
 				classpath: configurations.jarjar.asPath
-			jarjar(destfile: repackJar.archivePath) {
+			jarjar(destfile: repackJar.archiveFile.get()) {
 				configurations.jmustache.each { originalJar ->
 					zipfileset(src: originalJar, includes: "**/*.class")
 				}
@@ -70,7 +70,7 @@ dependencies {
 
 jar {
 	dependsOn jmustacheRepackJar
-	from(zipTree(jmustacheRepackJar.archivePath)) {
+	from(zipTree(jmustacheRepackJar.archiveFile.get())) {
 		include "org/springframework/restdocs/**"
 	}
 }