Docker image deploy: scale Heroku app size (#21369)

* Scale Heroku app size

* Make Heroku key a job level env var

.github/workflows/staging-deploy-pr-docker.yml

@@ -20,6 +20,8 @@ env:
 
 jobs:
   prepare:
+    env:
+      HEROKU_API_KEY: ${{ secrets.HEROKU_API_TOKEN }}
     if: >-
       ${{
         github.event.workflow_run.conclusion == 'success' &&
@@ -126,9 +128,11 @@ jobs:
               throw(err)
             }
 
+      - name: Scale Heroku App size
+        run: |
+          heroku ps:scale --app=${{ steps.create-app.outputs.app_name}} web=1:Standard-2X
+
       - name: Build, tag, push, and release the Docker image
-        env:
-          HEROKU_API_KEY: ${{ secrets.HEROKU_API_TOKEN }}
         run: |
           docker image build --target production_early_access -t registry.heroku.com/${{ steps.create-app.outputs.app_name}}/web .
           heroku container:login