Very large releases are still announced and checked

After every release, an automatic step posts the change’s announcement and checks that its delivery record was filed away. Both rely on GitHub’s list of the files the change touched, and GitHub stops that list at 3,000 files without saying so.

On a release larger than that, the step used to miss the announcement and the record, and report success while doing nothing. It now notices when the list has been cut short and uses the release’s own name to find the announcement and the record. When it cannot tell which release it is looking at, the alerts channel is told why.