Add keyboard shortcut to suppress prompt while deleting files/dirs (#9452)

Completes #7228.
Adds back Backspace as the main delete key binding and makes Linux
bindings consistent with macOS

Release Notes:
- ⌘-Delete/⌘-Backspace will now suppress deletion confirmation prompts
in project panel
([#7228](https://github.com/zed-industries/zed/issues/7228)).

assets/keymaps/default-linux.json

@@ -514,6 +514,9 @@
       "f2": "project_panel::Rename",
       "enter": "project_panel::Rename",
       "backspace": "project_panel::Delete",
+      "delete": "project_panel::Delete",
+      "ctrl-backspace": ["project_panel::Delete", { "skip_prompt": true }],
+      "ctrl-delete": ["project_panel::Delete", { "skip_prompt": true }],
       "ctrl-alt-r": "project_panel::RevealInFinder",
       "alt-shift-f": "project_panel::NewSearchInDirectory"
     }