Start building against Spring Integration 6.0.0-M4 snapshots

See gh-31624

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -1404,7 +1404,7 @@ bom {
 			]
 		}
 	}
-	library("Spring Integration", "6.0.0-M3") {
+	library("Spring Integration", "6.0.0-SNAPSHOT") {
 		group("org.springframework.integration") {
 			imports = [
 				"spring-integration-bom"

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-integration/src/main/java/smoketest/integration/SampleIntegrationApplication.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -23,7 +23,6 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 import org.springframework.integration.channel.DirectChannel;
 import org.springframework.integration.dsl.IntegrationFlow;
-import org.springframework.integration.dsl.IntegrationFlows;
 import org.springframework.integration.dsl.Pollers;
 import org.springframework.integration.dsl.SourcePollingChannelAdapterSpec;
 import org.springframework.integration.file.FileReadingMessageSource;
@@ -64,7 +63,7 @@ public class SampleIntegrationApplication {
 
 	@Bean
 	public IntegrationFlow integrationFlow(SampleEndpoint endpoint) {
-		return IntegrationFlows.from(fileReader(), new FixedRatePoller()).channel(inputChannel()).handle(endpoint)
+		return IntegrationFlow.from(fileReader(), new FixedRatePoller()).channel(inputChannel()).handle(endpoint)
 				.channel(outputChannel()).handle(fileWriter()).get();
 	}
 

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-parent-context/src/main/java/smoketest/parent/SampleParentContextApplication.java

@@ -25,7 +25,6 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.integration.channel.DirectChannel;
 import org.springframework.integration.dsl.IntegrationFlow;
-import org.springframework.integration.dsl.IntegrationFlows;
 import org.springframework.integration.dsl.Pollers;
 import org.springframework.integration.dsl.SourcePollingChannelAdapterSpec;
 import org.springframework.integration.file.FileReadingMessageSource;
@@ -74,7 +73,7 @@ public class SampleParentContextApplication {
 
 		@Bean
 		public IntegrationFlow integrationFlow(SampleEndpoint endpoint) {
-			return IntegrationFlows.from(fileReader(), new FixedRatePoller()).channel(inputChannel()).handle(endpoint)
+			return IntegrationFlow.from(fileReader(), new FixedRatePoller()).channel(inputChannel()).handle(endpoint)
 					.channel(outputChannel()).handle(fileWriter()).get();
 		}