Use a different color for ignored files in the project panel (#4227)

![Screenshot 2024-01-23 at 1 03
01 PM](https://github.com/zed-industries/zed/assets/326587/28b4e7e1-8847-40ff-aed6-0f4ede6b9007)


Release Notes:

- Fixed an issue where ignored files were not visually distinguished in
the project panel.
2d7d07173dMax Brunsfeld committed on 1/23/2024, 9:10:15 PM· committed by GitHubparents7ec68e04e970e9
1 file changedLine totals unavailable