doc/go1.22: document changes to vet loopclosure analyzer
cmd/vet no longer reports loopclosure bugs within files built at
GoVersion>=1.22.
For #61422.
Change-Id: I6f29373bb236822ece4e7ae35914859538b8d57b
Reviewed-on: https://go-review.googlesource.com/c/go/+/551376
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Alan Donovan <adonovan@google.com>
Run-TryBot: Tim King <taking@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>