Optimize Kotlin inline class checks

This commit fixes a performance regression caused by gh-31698,
and more specifically by KClass#isValue invocations which are slow since
they load the whole module to find the class to get the descriptor.

After discussing with the Kotlin team, it has been decided that only
checking for the presence of `@JvmInline` annotation is enough for
Spring use case.

As a consequence, this commit introduces a new
KotlinDetector#isInlineClass method that performs such check, and
BeanUtils, CoroutinesUtils and WebMVC/WebFlux InvocableHandlerMethod
have been refined to leverage it.

Closes gh-32334

spring-core/src/test/kotlin/org/springframework/core/KotlinDetectorTests.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2002-2024 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.core
+
+import org.assertj.core.api.Assertions
+import org.junit.jupiter.api.Test
+
+/**
+ * Kotlin tests for [KotlinDetector].
+ *
+ * @author Sebastien Deleuze
+ */
+class KotlinDetectorTests {
+
+	@Test
+	fun isKotlinType() {
+		Assertions.assertThat(KotlinDetector.isKotlinType(KotlinDetectorTests::class.java)).isTrue()
+	}
+
+	@Test
+	fun isNotKotlinType() {
+		Assertions.assertThat(KotlinDetector.isKotlinType(KotlinDetector::class.java)).isFalse()
+	}
+
+	@Test
+	fun isInlineClass() {
+		Assertions.assertThat(KotlinDetector.isInlineClass(ValueClass::class.java)).isTrue()
+	}
+
+	@Test
+	fun isNotInlineClass() {
+		Assertions.assertThat(KotlinDetector.isInlineClass(KotlinDetector::class.java)).isFalse()
+		Assertions.assertThat(KotlinDetector.isInlineClass(KotlinDetectorTests::class.java)).isFalse()
+	}
+
+	@JvmInline
+	value class ValueClass(val value: String)
+
+}