Align on usage of cross-fetch vs node-fetch in frontend vs backend packages

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

plugins/auth-backend/src/identity/IdentityClient.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import fetch from 'cross-fetch';
+import fetch from 'node-fetch';
 import { JWK, JWT, JWKS, JSONWebKey } from 'jose';
 import { BackstageIdentity } from '../providers';
 import { PluginEndpointDiscovery } from '@backstage/backend-common';

plugins/auth-backend/src/providers/aws-alb/provider.test.ts

@@ -50,7 +50,7 @@ const mockClaims = {
 };
 
 jest.mock('jose');
-jest.mock('cross-fetch', () => ({
+jest.mock('node-fetch', () => ({
   __esModule: true,
   default: async () => {
     return {

plugins/auth-backend/src/providers/aws-alb/provider.ts

@@ -21,7 +21,7 @@ import {
   SignInResolver,
 } from '../types';
 import express from 'express';
-import fetch from 'cross-fetch';
+import fetch from 'node-fetch';
 import * as crypto from 'crypto';
 import { KeyObject } from 'crypto';
 import { Logger } from 'winston';