Error serving Ember app after updating via ember-cli-update

Hi,
I am updating an ember app from v3.17.3 to v3.24 (the LTS version). Mac OS 10.13.6. I ran

`ember-cli-update --to ~3.24`

So far so good. After resolving a few merge conflicts and running `npm install`, I have

`ember --version` --> ember-cli: 3.24.0

But when I try `ember s` locally I get

> ...
> Build Error (broccoli-persistent-filter:EslintValidationFilter) in integration/components/analytics-charts-test.js
>
> ESLint configuration in /Users/user1/Documents/embApp/warlord/.eslintrc.js is invalid:
> - Unexpected top-level property "overrides[0].extends".
>
>
>
> Stack Trace and Error Report: /var/folders/n5/3gg0dqt57j317n_z9lkv7xfw0000gn/T/error.dump.6c67c97dfe3fcbd6a826413d05601c39.log

The log file is attached. .eslintrc.js is attached.
[log.txt](https://github.com/ember-cli/ember-cli-update/files/6865583/log.txt)
[eslintrc_copy.txt](https://github.com/ember-cli/ember-cli-update/files/6865571/eslintrc_copy.txt)

The analytics-charts-test.js file has nothing but the auto-generated test code. I did not write a test for that component.

Reverting .eslintrc.js to it's pre-update content (or just commenting out the `extends: ['plugin:node/recommended'],` does allow it it proceed past the initial point of failure, but then it gives

> /@ember/test-waiters/types/index.ts: Property specifiers expected type of array but got null

Also, running code-mods makes no difference. Same error when trying to serve. Note that code-mods fails at ember-test-helpers-codemod, although that doesn't stop the rest of the mods from running.

Appears that there is some issue in the download for 3.24, perhaps around ember test helpers? Anyone else seeing this? If someone can help, it would be much appreciated.

Thanks