JAVA-28922 add Hystrix deprecation note (eugenp#15545)

Author: kasramp

hystrix/pom.xml

@@ -8,6 +8,7 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
+        <!-- Hystrix is deprecated and it is not possible to upgrade it to Spring Boot 3 -->
         <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../parent-boot-2</relativePath>