Remove unused imports

Closes gh-31851

spring-beans/src/test/kotlin/org/springframework/beans/factory/BeanFactoryExtensionsTests.kt

@@ -21,7 +21,6 @@ import io.mockk.mockk
 import io.mockk.verify
 import org.junit.jupiter.api.Test
 import org.springframework.core.ResolvableType
-import kotlin.reflect.full.createInstance
 
 /**
  * Mock object based tests for BeanFactory Kotlin extensions.

spring-core/src/test/kotlin/org/springframework/aot/hint/ResourceHintsExtensionsTests.kt

@@ -20,7 +20,6 @@ import io.mockk.every
 import io.mockk.mockk
 import io.mockk.verify
 import org.junit.jupiter.api.Test
-import java.util.function.Consumer
 
 /**
  * Tests for [ResourceHints] Kotlin extensions.

spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/server/ServerRequestExtensions.kt

@@ -23,7 +23,6 @@ import kotlinx.coroutines.reactive.asFlow
 import org.springframework.core.ParameterizedTypeReference
 import org.springframework.http.MediaType
 import org.springframework.http.codec.multipart.Part
-import org.springframework.util.CollectionUtils
 import org.springframework.util.MultiValueMap
 import org.springframework.web.server.WebSession
 import reactor.core.publisher.Flux