### Godot version

v4.1.rc2.official [46424488e]

### System information

Godot v4.1.rc2 - Linux Mint 20 (Ulyana) - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2060 SUPER (nvidia; 515.105.01) - Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz (8 Threads)

### Issue description

Dragging and dropping a file to a new position inside its current folder, or onto the icon for its current folder - when that folder is the project root folder :res// - will be treated as though you were dropping a different file with the same name.

Expectation: for nothing to happen.

Also tried it in 4.0.3 and 4.1-dev3, where it behaves as expected.

https://github.com/godotengine/godot/assets/64640811/90de1120-dd92-41b8-b202-db77c343103a

### Steps to reproduce

1. New or existing project.
2. Click and drag a file in :res// in FileSystem dock.
3. Drop the file back into :res//.
4. Be prompted to overwrite or rename.

### Minimal reproduction project

N/A
if (p_force || old_display_mode != display_mode) {
		button_toggle_display_mode->set_pressed(display_mode == DISPLAY_MODE_SPLIT);
		switch (display_mode) {
			case DISPLAY_MODE_TREE_ONLY:
				tree->show();
				tree->set_v_size_flags(SIZE_EXPAND_FILL);
				if (display_mode == DISPLAY_MODE_TREE_ONLY) {
					toolbar2_hbc->show();
				} else {
					toolbar2_hbc->hide();
				}
				_update_tree(get_uncollapsed_paths());
				file_list_vb->hide();
				break;
			case DISPLAY_MODE_SPLIT:
				tree->show();
				tree->set_v_size_flags(SIZE_EXPAND_FILL);
				tree->ensure_cursor_is_visible();
				toolbar2_hbc->hide();
				_update_tree(get_uncollapsed_paths());
				file_list_vb->show();
				_update_file_list(true);
				break;
		}
		old_display_mode = display_mode;
	}
}
void FileSystemDock::_notification(int p_what) {