fix: Clear resource bundle cache on resource redeployment

Allows translations to be reloaded in development mode

For #20118

flow-server/src/main/java/com/vaadin/flow/hotswap/Hotswapper.java

@@ -26,6 +26,7 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.ResourceBundle;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
@@ -165,13 +166,14 @@ public void onHotswap(URI[] createdResources, URI[] modifiedResources,
                     "Hotswap resources change event ignored because VaadinService has been destroyed.");
             return;
         }
-        // no-op for the moment, just logging for debugging purpose
-        // entry point for future implementations, like reloading I18n provider
         if (LOGGER.isTraceEnabled()) {
             LOGGER.trace(
                     "Created resources: {}, modified resources: {}, deletedResources: {}.",
                     createdResources, modifiedResources, deletedResources);
         }
+
+        // Clear resource bundle cache so that translations (and other resources) are reloaded
+        ResourceBundle.clearCache();
     }
 
     private void onHotswapInternal(HashSet<Class<?>> classes,