cmd/go, cmd/internal/objabi: detect "devel" version by substring
These were the remaining instances in the main Go repo I found where a
Go version like "devel go1.25-
9ce47e66e8 Wed Mar 26 03:48:50 2025 -0700"
is considered to be a development version rather than a release version,
but the version "go1.25-devel_9ce47e66e8 Wed Mar 26 03:48:50 2025 -0700"
is not.
Update this in preparation of the move of "devel" from front to middle.
For #73372.
For #73369.
Change-Id: If5442ecb0751c08b3a1b4d1148193e501700b956
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/668355
Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>