Code completions are not baseline aligned

**Describe the bug**
Often, it looks like code completions are not baseline aligned. For example, in the screenshot below, you can see the dots don't line up vertically, with the completion being slightly lower than the original text. This results in visual jankiness while typing.

**Versions**
- Copilot for Xcode: 0.27.92
- Xcode: 16.1
- macOS: 15.1

**Steps to reproduce**
1. Set the Dark (Default) theme in Xcode with a 13 point SF Mono Medium font.
2. Begin typing; often completions aren't baseline aligned.

**Screenshots**
See above.

**Logs**

**Additional context**