feat: removed static from method getConcatenation

Author: jimoye244

lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java

@@ -5,7 +5,7 @@
 
 public class Lesson11 {
 
-  public static int[] getConcatenation(int[] nums) {
+  public int[] getConcatenation(int[] nums) {
     int lenOriginalArray = nums.length;
     int[] concatenatedArrays = new int[lenOriginalArray * 2];