This changes the Go `outline.scm` queries a bit so that we don't have
these stray whitespaces floating around. I'm sure there's more
improvements possible, but for now I think this makes it look less
wrong.

Release Notes:

- Improved outline and breadcrumbs for Go code.

## Before

![before](https://github.com/zed-industries/zed/assets/1185253/d2b93c41-639b-4819-b87e-d8456960c5a7)

## After

![after](https://github.com/zed-industries/zed/assets/1185253/1ff6efb1-75a4-487b-8947-f070073887d4)