fix: Class Anagrams should be declared as final

Author: alxkm

src/main/java/com/thealgorithms/strings/Anagrams.java

@@ -10,7 +10,7 @@
  * also the word binary into brainy and the word adobe into abode.
  * Reference from https://en.wikipedia.org/wiki/Anagram
  */
-public class Anagrams {
+public final class Anagrams {
     private Anagrams() {
     }