optimise and extract behaviour to separate file

public/app/features/dashboard-scene/scene/hoverHeaderOffsetBehavior.ts

@@ -0,0 +1,19 @@
+import { VizPanel } from '@grafana/scenes';
+
+import { DashboardGridItem } from './DashboardGridItem';
+
+export const hoverHeaderOffsetBehavior = (grid: DashboardGridItem) => {
+  const sub = grid.subscribeToState((newState, prevState) => {
+    if ([newState.y, prevState.y].includes(0) && newState.y !== prevState.y) {
+      grid.forEachChild((child) => {
+        if (child instanceof VizPanel && child.state.hoverHeader) {
+          child.setState({ hoverHeaderOffset: grid.state.y === 0 ? 0 : undefined });
+        }
+      });
+    }
+
+    return () => {
+      sub.unsubscribe();
+    };
+  });
+};

public/app/features/dashboard-scene/serialization/transformSaveModelToScene.ts

@@ -47,6 +47,7 @@ import { panelLinksBehavior, panelMenuBehavior } from '../scene/PanelMenuBehavio
 import { PanelNotices } from '../scene/PanelNotices';
 import { PanelTimeRange } from '../scene/PanelTimeRange';
 import { RowRepeaterBehavior } from '../scene/RowRepeaterBehavior';
+import { hoverHeaderOffsetBehavior } from '../scene/hoverHeaderOffsetBehavior';
 import { RowActions } from '../scene/row-actions/RowActions';
 import { setDashboardPanelContext } from '../scene/setDashboardPanelContext';
 import { createPanelDataProvider } from '../utils/createPanelDataProvider';
@@ -475,16 +476,6 @@ export function buildGridItemForLibPanel(panel: PanelModel) {
   });
 }
 
-const hoverHeaderOffsetBehavior = (grid: DashboardGridItem) => {
-  grid.subscribeToState(() => {
-    grid.forEachChild((child) => {
-      if (child instanceof VizPanel && child.state.hoverHeader) {
-        child.setState({ hoverHeaderOffset: grid.state.y === 0 ? 0 : undefined });
-      }
-    });
-  });
-};
-
 export function buildGridItemForPanel(panel: PanelModel): DashboardGridItem {
   const repeatDirection: RepeatDirection = panel.repeatDirection === 'h' ? 'h' : 'v';
   const repeatOptions = panel.repeat