fix: import statements

Author: saahil-mahato

src/test/java/com/thealgorithms/maths/FastExponentiationTest.java

@@ -1,6 +1,7 @@
 package com.thealgorithms.maths;
 
-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;