main.star: extend gotestjsonbuildtext=1 to NEXT_GO

We'll drop it from tip and the new release-branch.go1.24 branch as soon
as result_adapter is ready to handle events that contain ImportPath but
not Package fields, but that's not the case this week.

For golang/go#70402.
For golang/go#70435.

Change-Id: Ibd5ce399e2b8e072eb9066a1d304964b41f6cc1b
Reviewed-on: https://go-review.googlesource.com/c/build/+/634237
Reviewed-by: Michael Knyszek <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: dmitshur