Fix dropdown style for selecting editor on small viewports

Summary

Following the changes in !37985 (merged), the dropdown for selecting Web IDE or Gitpod has been using incorrect styling. /cc @mnichols1 @corneliusludmann

Steps to reproduce

Go to a project or repository page like gitlab while using a small viewport (mobile).

Relevant logs and/or screenshots

The button should use the behavior and style of the clone button below except for the color.

Current	Proposed