cmd/go: drop flaky part of TestGoTestJSON
cmd/go: drop flaky part of TestGoTestJSON

Still failing on builders. I give up.
(For example https://build.golang.org/log/4fa5ba031c2fab5df397ac894f8b81392a93728e.)

Change-Id: Ifa87813e27e1adfe9920c7e657b0ff129eb5bf2f
Reviewed-on: https://go-review.googlesource.com/78315
Reviewed-by: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

akutz/go,akutz/go,CAFxX/go,Cofyc/go,Cofyc/go,akutz/go,Cofyc/go,codestation/go,nawawi/go,CAFxX/go,nawawi/go,golang/go,josharian/go,christopher-henderson/Go,CAFxX/go,codestation/go,golang/go,Cofyc/go,codestation/go,codestation/go,golang/go,CAFxX/go,akutz/go,nawawi/go,cloudflare/go,codestation/go,nawawi/go,CAFxX/go,Cofyc/go,cloudflare/go,akutz/go,akutz/go,CAFxX/go,Cofyc/go,codestation/go,josharian/go,codestation/go,akutz/go,Cofyc/go,Cofyc/go,josharian/go,josharian/go,nawawi/go,codestation/go,golang/go,golang/go,cloudflare/go,cloudflare/go,cloudflare/go,josharian/go,cloudflare/go,golang/go,akutz/go,nawawi/go,golang/go,josharian/go,nawawi/go,cloudflare/go,golang/go,josharian/go,josharian/go,CAFxX/go,cloudflare/go,nawawi/go,CAFxX/go