Use try with resources instead of try-finally

See gh-39259

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/NestedJarFileTests.java

@@ -413,7 +413,7 @@ class NestedJarFileTests {
 	}
 
 	private List<String> collectComments(JarFile jarFile) throws IOException {
-		try {
+		try (jarFile) {
 			List<String> comments = new ArrayList<>();
 			Enumeration<JarEntry> entries = jarFile.entries();
 			while (entries.hasMoreElements()) {
@@ -424,9 +424,6 @@ class NestedJarFileTests {
 			}
 			return comments;
 		}
-		finally {
-			jarFile.close();
-		}
 	}
 
 }