go.dev: fix for new app deployment
go.dev: fix for new app deployment

Same problem as tour: now running in the repo root.

Change-Id: I5227b5c0d1d161e2af702e5d37979be000407813
Reviewed-on: https://go-review.googlesource.com/c/website/+/328211
Trust: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
Run-TryBot: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Dmitri Shuralyov <d181b7fea0ec87c86ba5a890ab716db52498e3ba@golang.org>

golang/website,golang/website,golang/website,golang/website,golang/website,golang/website,golang/website