[Dropdown]: cannot select item with keyboard

[scottnath]

What package(s) are you using?

• carbon-components 10.5.1
• carbon-components-react

Detailed description

In the dropdown examples on the carbon site:
https://www.carbondesignsystem.com/components/dropdown/code/
if I focus a dropdown, I can use the up/down arrow to highlight selections, but if I hit Enter the dropdown doesn’t make a selection.

Steps to reproduce the issue

1. go to https://www.carbondesignsystem.com/components/dropdown/code/
2. focus on any dropdown
3. hit enter to open dropdown
4. use keyboard up/down to focus on an option
5. no keys allow making a selection