main.star: remove known issues for recent clang15/boringcrypto builders

They've proven to work in all repositories and on all relevant branches.

Change-Id: I8023883ad83d8efbf804c6db123aec1ab6862810
Reviewed-on: https://go-review.googlesource.com/c/build/+/578536
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
4 files changed