Update release-please.yml config to use secrets.GITHUB_TOKEN

[NoopDog]

Overview

We use a PAT to authenticate "release-please", but this is not necessary. Instead, we can use secrets.GITHUB_TOKEN

The file to change:
https://github.com/DataBiosphere/data-browser/blob/main/.github/workflows/release-please.yml

Set up the token similar to
https://github.com/DataBiosphere/data-portal/blob/main/.github/workflows/release-please.yml

Don't change any other release-please config.