encoding/gob: make x509.Certificate marshalable again
The OID type is not exported data like most of the other x509 structs.
Using it in x509.Certificate made Certificate not gob-compatible anymore,
which breaks real-world code. As a temporary fix, make gob ignore
that field, making it work as well as it did in Go 1.21.
For Go 1.23, we anticipate adding a proper fix and removing the gob
workaround. See #65633 and #66249 for more details.
For #66249.
Fixes #65633.
Change-Id: Idd1431d15063b3009e15d0565cd3120b9fa13f61
Reviewed-on: https://go-review.googlesource.com/c/go/+/571095
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Roland Shoemaker <roland@golang.org>