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-context-support/src/main/java/org/springframework/cache/jcache/interceptor/JCacheOperationSourcePointcut.java

@@ -1,68 +0,0 @@
-/*
- * Copyright 2002-2023 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.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.cache.jcache.interceptor;
-
-import java.io.Serializable;
-import java.lang.reflect.Method;
-
-import org.springframework.aop.support.StaticMethodMatcherPointcut;
-import org.springframework.lang.Nullable;
-import org.springframework.util.ObjectUtils;
-
-/**
- * A Pointcut that matches if the underlying {@link JCacheOperationSource}
- * has an operation for a given method.
- *
- * @author Stephane Nicoll
- * @since 4.1
- * @deprecated since 6.0.10, as it is not used by the framework anymore
- */
-@Deprecated(since = "6.0.10", forRemoval = true)
-@SuppressWarnings("serial")
-public abstract class JCacheOperationSourcePointcut extends StaticMethodMatcherPointcut implements Serializable {
-
-	@Override
-	public boolean matches(Method method, Class<?> targetClass) {
-		JCacheOperationSource cas = getCacheOperationSource();
-		return (cas != null && cas.getCacheOperation(method, targetClass) != null);
-	}
-
-	/**
-	 * Obtain the underlying {@link JCacheOperationSource} (may be {@code null}).
-	 * To be implemented by subclasses.
-	 */
-	@Nullable
-	protected abstract JCacheOperationSource getCacheOperationSource();
-
-
-	@Override
-	public boolean equals(@Nullable Object other) {
-		return (this == other || (other instanceof JCacheOperationSourcePointcut that &&
-				ObjectUtils.nullSafeEquals(getCacheOperationSource(), that.getCacheOperationSource())));
-	}
-
-	@Override
-	public int hashCode() {
-		return JCacheOperationSourcePointcut.class.hashCode();
-	}
-
-	@Override
-	public String toString() {
-		return getClass().getName() + ": " + getCacheOperationSource();
-	}
-
-}