combobox-item with no checkbox or radio buttons

[LefterisKoumis]

I want to use a combobox where the combobox items don’t display any selection indicators—no checkboxes or radio buttons next to them. It was possible until version 3.0.3.  Thought of using select component but it lacks properties that I need. I think it can be done through CSS rendering the button not visible. 

Selection icons are not necessary when the selection mode is set to single.

[DitwanDPrice]

Created an issue to explore options for achieving this behavior. 

https://github.com/Esri/calcite-design-system/issues/13179

[LefterisKoumis1]

Why do we need selection icon if users has selection-mode="single"?