fix(combobox): prevent item selection on Enter when list is empty

[zeus-12]

fix: Combobox no longer selects items when list is empty in "With Multiple Selection" example

Description

Fixed a bug where pressing Enter in the combobox when "no items found" was displayed would incorrectly select the last highlighted item from before the list became empty.

Testing

1. Type text that results in "no items found"
2. Press Enter
3. Verify no item gets selected

[vercel]

@zeus-12 is attempting to deploy a commit to the sadmann7 Team on Vercel.

A member of the Team first needs to authorize it.

[sadmann7]

thanks a lot.