Replace wildcard import with explicit JUnit imports

Author: Ayush41

src/test/java/com/thealgorithms/recursion/FactorialTest.java

@@ -1,4 +1,5 @@
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;