src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts/NotebookEditorWidget/deleteNotebookCell
class NotebookEditorWidget:	async deleteNotebookCell(cell: ICellViewModel): Promise<boolean> {
		if (!this.viewModel) {
			return false;
		}

		if (this.viewModel.options.isReadOnly) {
			return false;
		}

		if (this._pendingLayouts?.has(cell)) {
			this._pendingLayouts.get(cell)!.dispose();
		}

		const index = this.viewModel.getCellIndex(cell);
		this.viewModel.deleteCell(index, true);
		return true;
	}