stop relayout if the list is disposed or cell is deleted.

src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts

@@ -793,6 +793,10 @@ export class NotebookEditorWidget extends Disposable implements INotebookEditor
 		}
 
 		let relayout = (cell: ICellViewModel, height: number) => {
+			if (this._isDisposed) {
+				return;
+			}
+
 			this.list?.updateElementHeight2(cell, height);
 		};
 
@@ -1014,6 +1018,10 @@ export class NotebookEditorWidget extends Disposable implements INotebookEditor
 			return false;
 		}
 
+		if (this.pendingLayouts.has(cell)) {
+			this.pendingLayouts.get(cell)!.dispose();
+		}
+
 		const index = this.notebookViewModel!.getCellIndex(cell);
 		this.notebookViewModel!.deleteCell(index, true);
 		return true;