Remove unused import

Author: Hardvan

src/test/java/com/thealgorithms/backtracking/SudokuSolverTest.java

@@ -1,7 +1,6 @@
 package com.thealgorithms.backtracking;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import org.junit.jupiter.api.Test;