Polish "Remove outdated Session's Cookie override"

Closes gh-45523

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/SessionTests.java

@@ -1,36 +0,0 @@
-/*
- * Copyright 2012-2023 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.boot.web.servlet.server;
-
-import org.junit.jupiter.api.Test;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-/**
- * Tests for {@link Session}.
- *
- * @author Phillip Webb
- */
-class SessionTests {
-
-	@Test // gh-38589
-	void getCookieIsBinaryBackCompatible() throws Exception {
-		Class<?> returnType = Session.class.getDeclaredMethod("getCookie").getReturnType();
-		assertThat(returnType.getName()).isEqualTo("org.springframework.boot.web.servlet.server.Session$Cookie");
-	}
-
-}