Make httpcore5-h2 classes available to Gradle tests

httpclient5 now requires classes in httpcore5-h2 in addition to those
in httpcore5.

See gh-34086

Author: wilkinsona

spring-boot-project/spring-boot-tools/spring-boot-gradle-test-support/src/main/java/org/springframework/boot/testsupport/gradle/testkit/GradleBuild.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * 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.
@@ -43,6 +43,7 @@
 import org.apache.commons.compress.archivers.ArchiveEntry;
 import org.apache.hc.client5.http.io.HttpClientConnectionManager;
 import org.apache.hc.core5.http.HttpRequest;
+import org.apache.hc.core5.http2.HttpVersionPolicy;
 import org.gradle.testkit.runner.BuildResult;
 import org.gradle.testkit.runner.GradleRunner;
 import org.gradle.util.GradleVersion;
@@ -123,7 +124,8 @@ private List<File> pluginClasspath() {
 				new File(pathOfJarContaining(LanguageSettings.class)),
 				new File(pathOfJarContaining(ArchiveEntry.class)), new File(pathOfJarContaining(BuildRequest.class)),
 				new File(pathOfJarContaining(HttpClientConnectionManager.class)),
-				new File(pathOfJarContaining(HttpRequest.class)), new File(pathOfJarContaining(Module.class)),
+				new File(pathOfJarContaining(HttpRequest.class)),
+				new File(pathOfJarContaining(HttpVersionPolicy.class)), new File(pathOfJarContaining(Module.class)),
 				new File(pathOfJarContaining(Versioned.class)),
 				new File(pathOfJarContaining(ParameterNamesModule.class)),
 				new File(pathOfJarContaining(JsonView.class)), new File(pathOfJarContaining(Platform.class)),