[release-branch.go1.17] cmd/go: remove mercurial from bitbucket vcs options
Mercurial was deprecated as of July 1, 2020 as per https://bitbucket.org/blog/sunsetting-mercurial-support-in-bitbucket
Fixes #50812.
Updates #50810.
Change-Id: I0d40f84aaa393905cae7c4bed8919b15de9a5f6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/371720
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Bryan Mills <bcmills@google.com>
(cherry picked from commit
5b1b80beb1a2a9a353738e80777d1e25cfdfa095)
Reviewed-on: https://go-review.googlesource.com/c/go/+/380996
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>