Fix alignment of note emoji btn on hover

What does this MR do and why?

Fix emoji dancing around on hover

Caused after migrating to GlDisclosureDropdown: !142201 (merged)

Screenshots or screen recordings

Before	After

How to set up and validate locally

Test emoji picker on:

• Issue
• Merge request
• Epic
• Work item
• Design
• Snippets

Links

• ✂️ UX Paper Cuts 16.9 → Pajamas Migrations (#430246 - closed)