### 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
} else if ((String(dd["type"]) == "files") || (String(dd["type"]) == "files_and_dirs") || (String(dd["type"]) == "resource")) {
					tree->set_drop_mode_flags(Tree::DROP_MODE_ON_ITEM | Tree::DROP_MODE_INBETWEEN);
				} else if ((String(dd["type"]) == "nodes")) {
					holding_branch = true;
					TreeItem *item = tree->get_next_selected(tree->get_root());
					while (item) {
						tree_items_selected_on_drag_begin.push_back(item);
						item = tree->get_next_selected(item);
					}
					list_items_selected_on_drag_begin = files->get_selected_items();
				}
			}
		} break;
		case NOTIFICATION_DRAG_END: {
			tree->set_drop_mode_flags(0);
			if (holding_branch) {
				holding_branch = false;
				_reselect_items_selected_on_drag_begin(true);
			}
		} break;
		case NOTIFICATION_THEME_CHANGED: {
			overwrite_dialog_scroll->add_theme_style_override("panel", get_theme_stylebox("panel", "Tree"));
			if (is_visible_in_tree()) {
				_update_display_mode(true);
			}
		} break;
		case EditorSettings::NOTIFICATION_EDITOR_SETTINGS_CHANGED: {
			
			button_reload->set_icon(get_theme_icon(SNAME("Reload"), SNAME("EditorIcons")));
			button_toggle_display_mode->set_icon(get_theme_icon(SNAME("Panels2"), SNAME("EditorIcons")));