Remove TODO related to already closed ticket

DEVSIX-5168

Author: Eugene Bochilo

src/test/java/com/itextpdf/html2pdf/css/w3c/css_flexbox/OverflowHoriz005Test.java

@@ -30,7 +30,6 @@ This file is part of the iText (R) project.
 //TODO DEVSIX-5087 support layout properties for FlexContainerRenderer
 //TODO DEVSIX-5086 support flex-wrap property
 //TODO DEVSIX-5164 support align-content
-//TODO DEVSIX-5137 support margin collapse
 @LogMessages(messages = @LogMessage(messageTemplate = LogMessageConstant.FLEX_PROPERTY_IS_NOT_SUPPORTED_YET, count = 4))
 public class OverflowHoriz005Test extends W3CCssTest {
     @Override