Add CHANGES note for [GL !2947]

(cherry picked from commit fcca6285)
71 jobs for !6325 with u/fanf2/dnssec-settime-ctime-v9_16 in 32 minutes and 3 seconds (queued for 6 seconds)
latest detached
Name Stage Failure
misc Precheck
$ diff -urNap CHANGES CHANGES.tmp
$ perl util/check-changes CHANGES
bad change number 5885.
Uploading artifacts for failed job
Uploading artifacts...
checklibs.out: found 1 matching files and directories

Uploading artifacts as "archive" to coordinator... 201 Created
id=2520420 responseStatus=201 Created token=jwreusXC
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1