[release-branch.go1.25] cmd/go/internal/gover: fix ModIsPrerelease for toolchain versions
We forgot to call the IsPrerelease function on FromToolchain(vers)
rather than on vers itself. IsPrerelase expects a version without the
"go" prefix. See the corresponding code in ModIsValid and ModIsPrefix
that call FromToolchain before passing the versions to IsValid and
IsLang respectively.
Fixes #74822
Change-Id: I3cf055e1348e6a9dc0334e414f06fe85eaf78024
Reviewed-on: https://go-review.googlesource.com/c/go/+/691655
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Matloob <matloob@golang.org>
Reviewed-by: Michael Matloob <matloob@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
(cherry picked from commit
69338a335ada5882b888fb7eabe0ad6f0e12c986)
Reviewed-on: https://go-review.googlesource.com/c/go/+/691958