[jdk-updates communication] Code-review policy changes

[Robert Mckenna]

Similarly to the JDK project [1] we are making some changes to the code review policy in jdk-updates:

1. Any new commit pushed to a PR after it has been approved will revert the state of the PR to be unapproved. This will mean the PR will require re-review.

2. The skara /clean command, which allows a Committer to override Skara's determination as to whether a PR is clean, will be disabled.

We intend to roll these changes out by the beginning of next week. (no earlier than this Friday, July 26)

    -Rob

[1] https://mail.openjdk.org/pipermail/jdk-dev/2024-June/009134.html