### Godot version

master

### System information

Godot v4.2.beta (0ea75d77c) - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2070 (NVIDIA; 31.0.15.3598) - Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz (12 Threads)

### Issue description

When any of the Import, Filesystem, Node, or History docks are floating, changing an editor feature crashes the engine.
Changing any setting or selecting a different profile triggers it.

This is because `EditorNode::_feature_profile_changed` assumes the docks are in a `TabContainer`, and if they are floating they aren't in one.


### Steps to reproduce

Make any of these docks floating: Import, Filesystem, Node, or History
Open Editor Features (Editor -> Manage Editor Features...)
Make a profile (if you have none) or change a setting on the existing profile

### Minimal reproduction project

n/a
ofs.x += s.x * 4;
				ofs.x += s.x;
			} break;
			case DOCK_SLOT_RIGHT_BR: {
				ofs.x += s.x * 4;
				ofs += s;
			} break;
		}
		Rect2 r(ofs, s);
		dock_select_rect[i] = r;
		r.position += Vector2(2, 5);
		r.size -= Vector2(4, 7);
		if (i == dock_select_rect_over_idx) {
			dock_select->draw_rect(r, used_selected);
		} else if (dock_slot[i]->get_tab_count() == 0) {
			dock_select->draw_rect(r, unused);
		} else {
			dock_select->draw_rect(r, used);
		}
		for (int j = 0; j < MIN(3, dock_slot[i]->get_tab_count()); j++) {
			int xofs = (r.size.width / 3) * j;
			Color c = used;
			if (i == dock_popup_selected_idx && (dock_slot[i]->get_current_tab() > 3 || dock_slot[i]->get_current_tab() == j)) {
				c = tab_selected;
			}
			dock_select->draw_rect(Rect2(2 + ofs.x + xofs, ofs.y, r.size.width / 3 - 1, 3), c);
		}
	}
}
void EditorNode::_save_editor_layout() {