Deprecate and set trailingSlash option to false

Closes gh-28552

spring-test/src/test/java/org/springframework/test/web/servlet/samples/spr/FormContentTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -50,7 +50,7 @@ public class FormContentTests {
 	@RestController
 	private static class Spr15753Controller {
 
-		@PutMapping
+		@PutMapping("/")
 		public String test(Data d) {
 			return String.format("d1:%s, d2:%s.", d.getD1(), d.getD2());
 		}