doc/go1.22: document ast.Object deprecation
The api.txt changes were originally recorded by mistake (sorry)
into go1.21.txt; see CL 504915, which made the actual change
in August.
Change-Id: If46b48d9714f01605888a6e975c1a03ccfce3b3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/547637
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
Commit-Queue: Alan Donovan <adonovan@google.com>