Add git awareness to file tab icons (#16637)

Before:
<img width="536" alt="Screenshot 2024-08-22 at 15 58 22"
src="https://github.com/user-attachments/assets/7d957f82-cb09-451e-b944-28d57220a718">

After:
<img width="542" alt="Screenshot 2024-08-22 at 15 58 32"
src="https://github.com/user-attachments/assets/fc203c90-903a-4c35-8af0-45cca66cb9d6">


Release Notes:

- N/A

---------

Co-authored-by: evrensen467 <146845123+evrensen467@users.noreply.github.com>

crates/workspace/Cargo.toml

@@ -39,6 +39,7 @@ db.workspace = true
 derive_more.workspace = true
 fs.workspace = true
 futures.workspace = true
+git.workspace = true
 gpui.workspace = true
 http_client.workspace = true
 itertools.workspace = true