Remove Webkit search cancel button for cross-browser consistency

Use same code as in MinervaNeue. For unknown reason, Chrome
decides in 2020 to suddenly show search cancel button.

Change-Id: I5c813a2ea68929c05f5d061d46c027934853dbf8

resources/skins.vector.styles/search.less

@@ -73,7 +73,7 @@
 	&::-webkit-search-cancel-button,
 	&::-webkit-search-results-button,
 	&::-webkit-search-results-decoration {
-		-webkit-appearance: textfield;
+		display: none;
 	}
 }