Move more of the playbook into conductor. The MPA command inputs are prone to human error.

Avoids that dynamic accidentally sneaks in, see https://dart.dev/tools/analysis#enabling-additional-type-checks

Move a few import directives to be in correct order. Fixes https://github.com/flutter/flutter/issues/130434

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

Fixes https://github.com/flutter/flutter/issues/129744
Part of https://github.com/flutter/flutter/issues/129847

Migrate the packages_autoroller script to push to
flutter-pub-roller-bot/flutter.git, rather than
fluttergithubbot/flutter.git.

Fixes https://github.com/flutter/flutter/issues/128067

The newly updated lint will soon flag for-each in collections.

See discussion: https://github.com/dart-lang/linter/pull/4383

/cc @goderbauer

[conductor] Roll engine whenever version is out of date

[conductor] Remove cherrypick option

* lerp documentation

* Remove Note, Note That from repo

* Improve BorderSide documentation.

* apply review comments

* [conductor] Remove CiYaml model

* Remove package:yaml

* Update pubspec checksum

* [conductor] Tag engine versions

* Move tag to repository

* update console link

* update test to include new console link

[flutter_conductor] log to stderr but do not crash conductor if branch name validation fails (#99181)

* support commits past tagged stable release

* make better expectations