Closes: #17543
Release Notes:
- **New Feature:** Introduced the ability to automatically remove files
and directories from the Zed project panel that are specified in
`.gitignore`.
- **Configuration Option:** This behavior can be controlled via the new
`project_panel.hide_gitignore` setting. By setting it to `true`, files
listed in `.gitignore` will be excluded from the project panel.
- **Toggle:** Ability to toggle this setting using the action
`ProjectPanel::ToggleHideGitIgnore`
```json
"project_panel": {
"hide_gitignore": true
},
```
This results in a cleaner and easier to browse project panel for
projects that generate a lot of object files like `xv6-riscv` or `linux`
without needing to tweak `file_scan_exclusions` on `settings.json`
**Preview:**
- With `"project_panel.hide_gitignore": false` (default, this is how zed
currently looks)

- With `"project_panel.hide_gitignore": true`

- Action `ProjectPanel::ToggleHideGitIgnore`
