### 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 (is_layout_rtl()) {
				button_hist_next->set_icon(get_theme_icon(SNAME("Back"), SNAME("EditorIcons")));
				button_hist_prev->set_icon(get_theme_icon(SNAME("Forward"), SNAME("EditorIcons")));
			} else {
				button_hist_next->set_icon(get_theme_icon(SNAME("Forward"), SNAME("EditorIcons")));
				button_hist_prev->set_icon(get_theme_icon(SNAME("Back"), SNAME("EditorIcons")));
			}
			if (file_list_display_mode == FILE_LIST_DISPLAY_LIST) {
				button_file_list_display_mode->set_icon(get_theme_icon(SNAME("FileThumbnail"), SNAME("EditorIcons")));
			} else {
				button_file_list_display_mode->set_icon(get_theme_icon(SNAME("FileList"), SNAME("EditorIcons")));
			}
			tree_search_box->set_right_icon(get_theme_icon(SNAME("Search"), SNAME("EditorIcons")));
			tree_search_box->set_clear_button_enabled(true);
			tree_button_sort->set_icon(get_theme_icon(SNAME("Sort"), SNAME("EditorIcons")));
			file_list_search_box->set_right_icon(get_theme_icon(SNAME("Search"), SNAME("EditorIcons")));
			file_list_search_box->set_clear_button_enabled(true);
			file_list_button_sort->set_icon(get_theme_icon(SNAME("Sort"), SNAME("EditorIcons")));
			
			bool new_always_show_folders = bool(EDITOR_GET("docks/filesystem/always_show_folders"));
			if (new_always_show_folders != always_show_folders) {
				always_show_folders = new_always_show_folders;
				_update_file_list(true);
			}
			
			_update_display_mode();
		} break;
	}
}
void FileSystemDock::_tree_multi_selected(Object *p_item, int p_column, bool p_selected) {