cv: switch tryjob update task kind to non-transactional
cv: switch tryjob update task kind to non-transactional

I don't see a good reason that this task needs to be submitted
transactionally.

R=robertocn

Bug: 1312255
Change-Id: Id2db467c4a27faa3bb6a308bf7e859634ee1376c
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/3780672
Commit-Queue: Yiwei Zhang <50b2a565e2e78c292794832469a30ce5abc9959c@google.com>
Auto-Submit: Yiwei Zhang <50b2a565e2e78c292794832469a30ce5abc9959c@google.com>
Reviewed-by: Roberto Carrillo <b31161e510fbb37f8f70fdcde11530d2bae88470@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go