Spring Introduce attribute support in Kotlin RouterFunction DSL

On current spring framework version (5.3.19), RouterFunction attributes are not supported by RouterFunction Kotlin DSL.

RouterFunction attributes is currently supported by Java Builder : - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RouterFunctionBuilder.java#L335 - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RouterFunctionBuilder.java#L350 - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webmvc/src/main/java/org/springframework/web/servlet/function/RouterFunctionBuilder.java#L328 - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webmvc/src/main/java/org/springframework/web/servlet/function/RouterFunctionBuilder.java#L343

But RouterFunction attributes support is missing from all Kotlin DSL : - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/server/RouterFunctionDsl.kt#L65 - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/server/CoRouterFunctionDsl.kt#L66 - https://github.com/spring-projects/spring-framework/blob/172102d225c916e2ca24b87aa0f0a74d824815b2/spring-webmvc/src/main/kotlin/org/springframework/web/servlet/function/RouterFunctionDsl.kt#L62