Fixes https://github.com/flutter/flutter/issues/129744

This change:

1. re-enables the Linux packages_autoroller
2. ensures we redact the token from appearing in any logs (in local testing I realized some failure logs might still expose the token)

What actually fixed authentication however was creating and uploading a new GitHub personal access token, not this change.

It's currently failing post-submit because being marked `bringup` it is running in the try pool, which does not have permissions to access the cloud KMS. However, I ran a LED build in the prod pool that succeeded:

https://ci.chromium.org/raw/build/logs.chromium.org/flutter/led/fujino_google.com/3a8f128c352fca53a9a29f1e7eab6c3ed24f3bb2a5feb196ea1a69127540e8a6/+/build.proto?server=chromium-swarm.appspot.com