Polish "Replace deprecated method getBuildDir()"

See gh-31416

buildSrc/src/main/java/org/springframework/build/api/ApiDiffPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -131,9 +131,9 @@ public class ApiDiffPlugin implements Plugin<Project> {
 	}
 
 	private File getOutputFile(String baseLineVersion, Project project) {
-		Path outDir = Paths.get(project.getRootProject()
-						.getLayout().getBuildDirectory().getAsFile().get().getAbsolutePath(),
-				"reports", "api-diff",
+		String buildDirectoryPath = project.getRootProject()
+				.getLayout().getBuildDirectory().getAsFile().get().getAbsolutePath();
+		Path outDir = Paths.get(buildDirectoryPath, "reports", "api-diff",
 				baseLineVersion + "_to_" + project.getRootProject().getVersion());
 		return project.file(outDir.resolve(project.getName() + ".html").toString());
 	}

settings.gradle

@@ -47,7 +47,8 @@ rootProject.children.each {project ->
 settings.gradle.projectsLoaded {
 	gradleEnterprise {
 		buildScan {
-			File buildDir = settings.gradle.rootProject.getLayout().getBuildDirectory().getAsFile().get()
+			File buildDir = settings.gradle.rootProject
+					.getLayout().getBuildDirectory().getAsFile().get()
 			buildDir.mkdirs()
 			new File(buildDir, "build-scan-uri.txt").text = "(build scan not generated)"
 			buildScanPublished { scan ->