techdocs: do not use cross-fetch in backend

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

plugins/techdocs-backend/src/service/DocsSynchronizer.test.ts

@@ -31,7 +31,7 @@ import { DocsSynchronizer, DocsSynchronizerSyncOpts } from './DocsSynchronizer';
 
 jest.mock('../DocsBuilder');
 
-jest.mock('cross-fetch', () => ({
+jest.mock('node-fetch', () => ({
   __esModule: true,
   default: async () => {
     return {

plugins/techdocs-backend/src/service/DocsSynchronizer.ts

@@ -24,7 +24,7 @@ import {
   PreparerBuilder,
   PublisherBase,
 } from '@backstage/techdocs-common';
-import fetch from 'cross-fetch';
+import fetch from 'node-fetch';
 import { PassThrough } from 'stream';
 import * as winston from 'winston';
 import { TechDocsCache } from '../cache';