remove requirement for the token

[ndelangen]

Remove the need to set a GitHub token

[linear]

CH-1052 GITHUB_TOKEN is possibly not necessary anymore

💬Talk to a developer

Hi, I am setting up a github action for chromatic and I see you ask to send a github token:
```
token: ${{ secrets.GITHUB_TOKEN }}
```

But in the source code I can't see where that is used: https://github.com/chromaui/chromatic-cli/blob/next/action-src/main.ts

I do see it used to be used 2 years ago (I didn't check exactly when the line getInput('token') was removed). Could it be that it's not needed anymore? Can I safely remove it, and if so can you remove it from the docs too? Thanks!