refactor: Update basic examples to Java 25

Signed-off-by: Manoel Campos <[email protected]>

Author: manoelcampos

src/main/java/org/cloudsimplus/examples/BasicFirstExample.java

@@ -74,7 +74,7 @@ public class BasicFirstExample {
     private List<Cloudlet> cloudletList;
     private Datacenter datacenter0;
 
-    public static void main(String[] args) {
+    static void main() {
         new BasicFirstExample();
     }
 

src/main/java/org/cloudsimplus/examples/ReducedExample.java

@@ -53,8 +53,8 @@
  * @since CloudSim Plus 1.0
  * @see BasicFirstExample
  */
-class ReducedExample {
-    public static void main(String[] args) {
+public class ReducedExample {
+    void main() {
         //tag::cloudsimplus-reduced-example[]
         //Enables just some level of log messages
         //Log.setLevel(ch.qos.logback.classic.Level.WARN);