When using railway environment new, how do I prevent a github connection and auto deploy?

Question

Hi, I'm writing my own PR environment github workflow.

One part of it is the environment creation/update:
```yml
- name: Ensure Railway PR Environment
        id: railway_env
        env:
          RAILWAY_API_TOKEN: ${{ secrets.RAILWAY_API_TOKEN }}
        run: |
          railway link --project ${{ env.RAILWAY_PROJECT_ID }} --environment ${{ env.RAILWAY_DUPLICATE_ENV_ID }}

if railway env ${{ env.PR_ENV_NAME }} --json > /dev/null 2>&1; then
            echo "Railway environment already exists: ${{ env.PR_ENV_NAME }}"
            echo "env_created=false" >> $GITHUB_OUTPUT
            railway link --project ${{ env.RAILWAY_PROJECT_ID }} --environment ${{ env.PR_ENV_NAME }}
            railway variables set "DATABASE_URL=${{ steps.neon.outputs.db_url }}" --service ${{ env.RAILWAY_BACKEND_SERVICE_ID }}
          else
            echo "Creating new Railway environment: ${{ env.PR_ENV_NAME }}"
            echo "env_created=true" >> $GITHUB_OUTPUT
            railway environment new ${{ env.PR_ENV_NAME }} \
              --copy ${{ env.RAILWAY_DUPLICATE_ENV_ID }} \
              --service-variable ${{ env.RAILWAY_BACKEND_SERVICE_ID }} "DATABASE_URL=${{ steps.neon.outputs.db_url }}" \
              --service-variable ${{ env.RAILWAY_BACKEND_SERVICE_ID }} "AUTH_COOKIE_DOMAIN=.up.railway.app"
          fi
```

Previously I had --service-variable set the git branch name on the services, but I since removed that, however the connection is still automatically made, and I don't know where. Is there some default behavior going on?