style: enable HideUtilityClassConstructor in checkstyle (#5147)

src/main/java/com/thealgorithms/datastructures/hashmap/hashing/Main.java

@@ -2,7 +2,9 @@ package com.thealgorithms.datastructures.hashmap.hashing;
 
 import java.util.Scanner;
 
-public class Main {
+public final class Main {
+    private Main() {
+    }
 
     public static void main(String[] args) {
         int choice, key;

src/main/java/com/thealgorithms/datastructures/hashmap/hashing/MainCuckooHashing.java

@@ -2,7 +2,9 @@ package com.thealgorithms.datastructures.hashmap.hashing;
 
 import java.util.Scanner;
 
-public class MainCuckooHashing {
+public final class MainCuckooHashing {
+    private MainCuckooHashing() {
+    }
 
     public static void main(String[] args) {
         int choice, key;

src/main/java/com/thealgorithms/datastructures/hashmap/hashing/MajorityElement.java

@@ -8,7 +8,9 @@ This class finds the majority element(s) in an array of integers.
 A majority element is an element that appears more than or equal to n/2 times, where n is the length
 of the array.
 */
-public class MajorityElement {
+public final class MajorityElement {
+    private MajorityElement() {
+    }
     /*
    This method returns the majority element(s) in the given array of integers.
    @param nums: an array of integers