GH-9863: Remove deprecated PollerMetadata.sendTimeout option

Issue link: #9863

The `PollerMetadata.sendTimeout` has been deprecated in previous versions
in favor of ``

* Remove `PollerMetadata.sendTimeout` and `PollerSpec.sendTimeout`
in favor of `SourcePollingChannelAdapterSpec.sendTimeout`

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/dsl/PollerSpec.java

@@ -189,17 +189,6 @@ public PollerSpec taskExecutor(Executor taskExecutor) {
 		return this;
 	}
 
-	/**
-	 * The timeout for blocking send on channels.
-	 * @param sendTimeout the timeout to use.
-	 * @return the spec.
-	 * @deprecated in favor of {@link SourcePollingChannelAdapterSpec#sendTimeout(long)}
-	 */
-	@Deprecated(forRemoval = true, since = "6.3.9")
-	public PollerSpec sendTimeout(long sendTimeout) {
-		return this;
-	}
-
 	@Override
 	public Map<Object, String> getComponentsToRegister() {
 		return this.componentsToRegister;

spring-integration-core/src/main/java/org/springframework/integration/scheduling/PollerMetadata.java

@@ -68,8 +68,6 @@ public class PollerMetadata {
 
 	private Executor taskExecutor;
 
-	private long sendTimeout;
-
 	private TransactionSynchronizationFactory transactionSynchronizationFactory;
 
 	public void setTransactionSynchronizationFactory(
@@ -138,16 +136,6 @@ public Executor getTaskExecutor() {
 		return this.taskExecutor;
 	}
 
-	@Deprecated(forRemoval = true, since = "6.3.9")
-	public long getSendTimeout() {
-		return this.sendTimeout;
-	}
-
-	@Deprecated(forRemoval = true, since = "6.3.9")
-	public void setSendTimeout(long sendTimeout) {
-		this.sendTimeout = sendTimeout;
-	}
-
 	/**
 	 * Return the default {@link PollerMetadata} bean if available.
 	 * @param beanFactory BeanFactory for lookup, must not be null.