Simplify comments to use logging instead of the Github API

[doriable]

This PR does the following:

• Converts previous comments into workflow annotations instead, removing the need to use the Github API
• This also removes the dependency on the github.token (so users no longer need to provide a Github token) and does not require the Github Action to extract owner, repository, and pullRequestNumber from github.context
• Lint errors no longer show up as comments/conversations, but are instead annotations that only show up in the Files tab of a pull request
• Allows us to use the "Unchanged files with check annotations" feature, which shows annotations for lint errors, even for files outside of the PR -- this was testing on an internal repository

We plan to make a similar change to buf-breaking-action

[johanbrandhorst]

Nice, much simpler!

[amckinney]

Awesome work, I'm so happy to get rid of all this GitHub API code 👏

[amckinney]

Everything looks great, but consider including a more meaningful message rather than an empty error.

    return {
        message: `buf found ${result.fileAnnotations.length} lint failures.\n
    };