Merge branch '3.1.x' into 3.2.x

Closes gh-40464

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/run/BootTestRunIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -113,7 +113,7 @@ class BootTestRunIntegrationTests {
 		else {
 			assertThat(result.getOutput())
 				.contains("Main class name has not been configured and it could not be resolved from classpath "
-						+ String.join(File.separator, "build", "classes", "java", "test"));
+						+ canonicalPathOf("build/classes/java/test"));
 		}
 	}