Don't wait for PR approval when PR author is a maintainer

[cpu]

An idea from djc in discord:

would be nice if the benchmarking bot knew it doesn't need to wait for approval on PRs where the author is an org maintainer

I think this would be a fairly small lift: we already have the code in place to check when a PR is approved that the approver has an allowed account association. Likely we just need to adjust the event processing for a new PR to skip requiring an approval or a comment if the author has such an association.