Announcing review approval process changes

[tison]

Hi contributors! On behalf of our infra team, I’d like to announce a consensus reached last week.

UPDATE: Changes deployed since 2021-05-31

Issue: Count LGTM only for review approval

We are supporting multiple kind of review approval (LGTM) reactions so far. From time to time it causes a number of confusions and build unnecessary approaches since GitHub already provide such mechanism.

https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/approving-a-pull-request-with-required-reviews

You can see the decision making progress on the issue and we are gonna drop support of /lgtm alike review approval reactions in the near future.

Comment on the issue if you have further concern.