[5.0.0] transitive dependencies make "FunctionEndpointInitializer" initialize on webmvc demo

[SingKS8]

Describe the bug Please provide details of the problem, including the version of Spring Cloud that you are using.

I have upgraded my demo, version updates is below spring boot 3.5.8 -> 4.0.0 (webmvc) spring-cloud-starter-function-web 4.3.0 -> 5.0.0 (cloud 2025.1.0)

Two dependencies of "spring-cloud-function-web", "spring-boot-webclient" and "spring-boot-webtestclient" are not optional, both of them have transitive dependency "spring-webflux".

Exception in thread "main" java.lang.IllegalArgumentException: Unable to instantiate factory class [org.springframework.cloud.function.web.function.FunctionEndpointInitializer] for factory type [org.springframework.context.ApplicationContextInitializer]
	at org.springframework.core.io.support.SpringFactoriesLoader$FailureHandler.lambda$throwing$0(SpringFactoriesLoader.java:632)
	at org.springframework.core.io.support.SpringFactoriesLoader$FailureHandler.lambda$handleMessage$0(SpringFactoriesLoader.java:656)
	at org.springframework.core.io.support.SpringFactoriesLoader.instantiateFactory(SpringFactoriesLoader.java:225)
	at org.springframework.core.io.support.SpringFactoriesLoader.load(SpringFactoriesLoader.java:201)
	at org.springframework.core.io.support.SpringFactoriesLoader.load(SpringFactoriesLoader.java:157)
	at org.springframework.boot.SpringApplication.getSpringFactoriesInstances(SpringApplication.java:481)
	at org.springframework.boot.SpringApplication.getSpringFactoriesInstances(SpringApplication.java:477)
	at org.springframework.boot.SpringApplication.<init>(SpringApplication.java:281)
	at org.springframework.boot.SpringApplication.<init>(SpringApplication.java:260)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1374)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1363)
	at xyz.opcal.demo.FunctionWebApplication.main(FunctionWebApplication.java:10)
Caused by: java.lang.NoClassDefFoundError: org/springframework/boot/webflux/error/ErrorAttributes
	at java.base/java.lang.Class.getDeclaredConstructors0(Native Method)
	at java.base/java.lang.Class.privateGetDeclaredConstructors(Class.java:3551)
	at java.base/java.lang.Class.getConstructors(Class.java:2229)
	at org.springframework.core.io.support.SpringFactoriesLoader$FactoryInstantiator.findConstructor(SpringFactoriesLoader.java:400)
	at org.springframework.core.io.support.SpringFactoriesLoader$FactoryInstantiator.forClass(SpringFactoriesLoader.java:390)
	at org.springframework.core.io.support.SpringFactoriesLoader.instantiateFactory(SpringFactoriesLoader.java:221)
	... 9 more
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.webflux.error.ErrorAttributes
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
	... 15 more

Sample If possible, please provide a test case or sample application that reproduces the problem. This makes it much easier for us to diagnose the problem and to verify that we have fixed it.