src/vs/workbench/contrib/notebook/browser/notebookKernelActionViewItem.ts/NotebooKernelActionViewItem/_update
class NotebooKernelActionViewItem:	protected _update(): void {
		const notebook = this._editor.viewModel?.notebookDocument;

		if (!notebook) {
			this._resetAction();
			return;
		}

		const info = this._notebookKernelService.getMatchingKernel(notebook);
		this._updateActionFromKernelInfo(info);
	}