[API] Tweak ImString tests

imgui-binding/src/test/java/imgui/ImVec2Test.java

@@ -3,7 +3,7 @@ package imgui;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class ImVec2Test {
     @Nested