go.dev: make cloudbuild.yaml safe to run in golang-org project

Setting --project=go-discovery on the command lines is enough
to do the deploy directly from golang-org Cloud Build, avoiding
an inline cloudbuild.yaml in the trigger configuration that was
reinvoking the cloud build in the other project.

(I gave the golang-org cloud build account permission to be an
"App Engine Deployer" for go-discovery.)

Change-Id: Iafed260f96b9adcf7442a9fa0df2cc44ea28a2ea
Reviewed-on: https://go-review.googlesource.com/c/website/+/328690
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
diff --git a/go.dev/cloudbuild.yaml b/go.dev/cloudbuild.yaml
index 080164e..7d641d1 100644
--- a/go.dev/cloudbuild.yaml
+++ b/go.dev/cloudbuild.yaml
@@ -12,11 +12,11 @@
     dir: go.dev
   - name: "gcr.io/cloud-builders/gcloud"
     entrypoint: bash
-    args: ["./go-app-deploy.sh", "go.dev/app.yaml"]
+    args: ["./go-app-deploy.sh", "--project=go-discovery", "go.dev/app.yaml"]
   - name: 'mirror.gcr.io/library/golang'
     args: [
       "go", "run", "./cmd/versionprune", "--dry_run=false",
-      "--project=$PROJECT_ID", "--service=go-dev",
+      "--project=go-discovery", "--service=go-dev",
     ]
     dir: go.dev