update publishing automation integration

[devoncarew]

• re-enable publishing automation, and update the config to listen for PR label changes (this will let us support the new publish-ignore-warnings label to suppress publish dry-run warnings)
• address Re-enable publish verification task #1995
• tweak the PR labeling workflow slightly (use type-infra instead of infra)

[devoncarew]

@annagrin - this updates the automation integration here to support using a label to ignore publishing warnings on a PR. However, I don't know that this helps the situation for webdev generally. From the current warnings:

* Your dependency on "dwds" should allow more than one version. For example:
  dependencies:
    dwds: ^18.0.0
  Constraints that are too tight will make it difficult for people to use your package
  along with other packages that also depend on "dwds".

* Packages with an SDK constraint on a pre-release of the Dart SDK should themselves be published as a pre-release version. If this package needs Dart version 3.0.0-188.0.dev, consider publishing the package as a pre-release instead.
  See https://dart.dev/tools/pub/publishing#publishing-prereleases For more information on pre-releases.

The 2nd one seeing like something webdev will hit periodically, as we roll out new language features over time. And the first one seems like a persistent setup in the pubspec - done intentionally to help reduce issues with vm service protocol changes.

So, YMMV whether you want to accept this PR or not -

[annagrin]

LGTM! Thanks @devoncarew !

[annagrin]

The 2nd one seeing like something webdev will hit periodically, as we roll out new language features over time. And the first one seems like a persistent setup in the pubspec - done intentionally to help reduce issues with vm service protocol changes.

You are correct about the reasons. I am accepting the PR so we can see if publishing works next time we need to publish a package. Thanks for the fast response!