Add hints to instantiate HttpService group adapters

See gh-35038

Signed-off-by: Olga Maciaszek-Sharma <olga.maciaszek-sharma@broadcom.com>

spring-web/src/main/java/org/springframework/web/client/support/RestClientHttpServiceGroupAdapterRuntimeHints.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2002-2025 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.web.client.support;
+
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.aot.hint.MemberCategory;
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.RuntimeHintsRegistrar;
+import org.springframework.aot.hint.TypeReference;
+
+/**
+ * A {@link RuntimeHintsRegistrar} implementation that adds hints for {@link RestClientHttpServiceGroupAdapter}.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 7.0
+ */
+public class RestClientHttpServiceGroupAdapterRuntimeHints implements RuntimeHintsRegistrar {
+
+	@Override
+	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
+		hints.reflection()
+				.registerType(TypeReference.of(RestClientHttpServiceGroupAdapter.class),
+						MemberCategory.INVOKE_PUBLIC_CONSTRUCTORS);
+	}
+}