runtime: remove cloudwego/frugal unused linkname from comment
frugal no longer uses these methods from next Go version
Fixes #69222
Change-Id: Ie71de0752cabef7d5584d3392d6e5920ba742350
Reviewed-on: https://go-review.googlesource.com/c/go/+/609918
Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>