Fix dragging when navigator is docked (#1586)

Fixed conditional rendering of tree preview.

## Code Review

- [ ] hi @kof, I need you to do
  - conceptual review (architecture, feature-correctness)
  - detailed review (read every line)
  - test it on preview

## Before requesting a review

- [ ] made a self-review
- [ ] added inline comments where things may be not obvious (the "why",
not "what")

## Before merging

- [ ] tested locally and on preview environment (preview dev login:
5de6)
- [ ] updated [test
cases](https://github.com/webstudio-is/webstudio-builder/blob/main/apps/builder/docs/test-cases.md)
document
- [ ] added tests
- [ ] if any new env variables are added, added them to `.env.example`
and the `builder/env-check.js` if mandatory

Co-authored-by: Oleg Isonen <oleg008@gmail.com>

apps/builder/app/builder/features/inspector/inspector.tsx

@@ -36,18 +36,10 @@ const contentStyle = {
   overflow: "auto",
 };
 
-// separate component to avoid inspetor updates on drag when navigator is undocked
-const NavigatorTreePreview = () => {
-  const [dragAndDropState] = useDragAndDropState();
-  if (dragAndDropState.isDragging) {
-    return <NavigatorTree />;
-  }
-  return null;
-};
-
 export const Inspector = ({ publish, navigatorLayout }: InspectorProps) => {
   const selectedInstance = useStore(selectedInstanceStore);
   const tabsRef = useRef<HTMLDivElement>(null);
+  const [dragAndDropState] = useDragAndDropState();
 
   const [tab, setTab] = useState("style");
 
@@ -59,8 +51,8 @@ export const Inspector = ({ publish, navigatorLayout }: InspectorProps) => {
     }
   }, [selectedInstance, tab]);
 
-  if (navigatorLayout === "docked") {
-    return <NavigatorTreePreview />;
+  if (navigatorLayout === "docked" && dragAndDropState.isDragging) {
+    return <NavigatorTree />;
   }
 
   if (selectedInstance === undefined) {