Remove APIs deprecated for removal in 6.2

This commit removes the following obsolete and deprecated APIs.

- org.springframework.util.Base64Utils

- org.springframework.cache.jcache.interceptor.JCacheOperationSourcePointcut

- org.springframework.http.client.AbstractClientHttpResponse

- org.springframework.http.client.ClientHttpResponse.getRawStatusCode()

- org.springframework.http.client.observation.ClientHttpObservationDocumentation.HighCardinalityKeyNames.CLIENT_NAME

- org.springframework.web.reactive.function.client.ClientHttpObservationDocumentation.HighCardinalityKeyNames.CLIENT_NAME

- org.springframework.web.filter.reactive.ServerWebExchangeContextFilter.get(Context)

- org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler.handleBindException(...)

- org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleBindException(...)

Closes gh-30608

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ClientHttpObservationDocumentation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -132,20 +132,6 @@ public enum ClientHttpObservationDocumentation implements ObservationDocumentati
 			public String asString() {
 				return "http.url";
 			}
-		},
-
-		/**
-		 * Client name derived from the request URI host.
-		 * @deprecated in favor of {@link LowCardinalityKeyNames#CLIENT_NAME};
-		 * scheduled for removal in 6.2. This will be available both as a low and
-		 * high cardinality key value.
-		 */
-		@Deprecated(since = "6.0.5", forRemoval = true)
-		CLIENT_NAME {
-			@Override
-			public String asString() {
-				return "client.name";
-			}
 		}
 
 	}