fix: fix layout scroll in Vaadin 25

Author: javier-godoy

src/main/java/com/flowingcode/vaadin/addons/demo/SplitLayoutDemo.java

@@ -41,6 +41,7 @@ public SplitLayoutDemo(Component demo, String sourceUrl, SourcePosition sourcePo
   }
 
   public SplitLayoutDemo(Component demo, List<SourceCodeTab> tabs) {
+    setClassName("commons-demo-split-layout");
     getContent().setOrientation(Orientation.HORIZONTAL);
 
     Map<String, String> properties = new HashMap<>();

src/main/resources/META-INF/resources/frontend/styles/commons-demo/shared-styles.css

@@ -43,4 +43,7 @@ code-highlighter code {
 	right: 10px;
 	top: 10px;
 	cursor: pointer;
-}
+}
+
+.commons-demo-split-layout { overflow: hidden }
+.commons-demo-split-layout > [slot] { overflow: auto; }