Update GenerateSubsetsTest.java

Author: Tuhinm2002

src/test/java/com/thealgorithms/Recursion/GenerateSubsetsTest.java

@@ -5,7 +5,7 @@
 import java.util.List;
 import org.junit.jupiter.api.Test;
 
-public class GenerateSubsetsTest {
+public final class GenerateSubsetsTest {
 
     @Test
     void subsetRecursionTestOne() {