Add note about potential resource exhaustion when Client is not singleton in FeignClientFactoryBean

Signed-off-by: 98001yash <yashchauhan.gaya@gmail.com>

Author: 98001yash

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/FeignClientFactoryBean.java

@@ -483,6 +483,9 @@ <T> T getTarget() {
 		if (StringUtils.hasText(url) && !url.startsWith("http://") && !url.startsWith("https://")) {
 			url = "http://" + url;
 		}
+		// NOTE: The Client bean should ideally be configured as a singleton.
+		// Repeated resolution of Client instances may lead to resource exhaustion
+		// (e.g., connection pools, threads) if not properly managed.
 		Client client = getOptional(feignClientFactory, Client.class);
 		if (client != null) {
 			if (client instanceof FeignBlockingLoadBalancerClient) {