fix build errors

Author: tavin

src/MySTMarkdownCell.tsx

@@ -21,7 +21,6 @@ import { selectAll } from 'unist-util-select';
 
 import { PromiseDelegate } from '@lumino/coreutils';
 import { JupyterCellProvider } from './JupyterCellProvider';
-import { IRenderMimeRegistry } from '@jupyterlab/rendermime';
 
 import { ObservableValue } from '@jupyterlab/observables';
 
@@ -31,14 +30,6 @@ export class MySTMarkdownCell
 {
   private _doneRendering = new PromiseDelegate<void>();
 
-  private __rendermime: IRenderMimeRegistry;
-
-  constructor(options: MarkdownCell.IOptions) {
-    super(options);
-
-    this.__rendermime = options.rendermime;
-  }
-
   myst: {
     pre?: GenericParent;
     post?: GenericParent;
@@ -107,8 +98,8 @@ export class MySTMarkdownCell
       <ThemeProvider
         theme={Theme.light}
         Link={linkFactory(
-          this.__rendermime.resolver,
-          this.__rendermime.linkHandler
+          notebook.rendermime.resolver,
+          notebook.rendermime.linkHandler
         )}
         renderers={renderers}
       >

src/myst.ts

@@ -56,10 +56,7 @@ export function markdownParse(text: string): Root {
   return mdast as Root;
 }
 
-
-export function renderNotebook(
-  notebook: StaticNotebook
-): undefined | Promise<void> {
+export function renderNotebook(notebook: StaticNotebook): Promise<void> {
   const cells = getCellList(notebook)?.filter(
     // In the future, we may want to process the code cells as well, but not now
     cell => cell.model.type === 'markdown'