[[PR Description]]

Before: 

![CleanShot 2023-12-18 at 13 10
14@2x](https://github.com/zed-industries/zed/assets/1714999/a0e536c3-b5bf-45e2-893b-89b1ae7b4c47)

After:

![CleanShot 2023-12-18 at 13 10
36@2x](https://github.com/zed-industries/zed/assets/1714999/5d66a4a9-cc19-420d-82c7-58ec5cd264e4)

One known issue:

The "Sign in to enable collaboration" text below the button should be
centered, but it looks like label is reserving the full width. Need to
look in to that.

Release Notes:

- N/A