Add missing "since" in @Deprecated

See gh-34942

Signed-off-by: Yanming Zhou <zhouyanming@gmail.com>

spring-test/src/main/java/org/springframework/test/web/servlet/setup/StubWebApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -418,7 +418,7 @@ class StubWebApplicationContext implements WebApplicationContext {
 			return BeanUtils.instantiateClass(beanClass);
 		}
 
-		@Deprecated
+		@Deprecated(since = "6.1")
 		@Override
 		public Object createBean(Class<?> beanClass, int autowireMode, boolean dependencyCheck) {
 			return BeanUtils.instantiateClass(beanClass);