how to use build-time secrets with Astro

17:59:51.389    01:59:51 [ERROR] [vite] x Build failed in 10ms
17:59:51.594    [EnvInvalidVariables] [astro-env-plugin] The following environment variables defined in `env.schema` are invalid:
17:59:51.595    
17:59:51.595    - SPOTIFY_REFRESH_TOKEN is missing
17:59:51.595    
17:59:51.595      Error reference:
17:59:51.596        https://docs.astro.build/en/reference/errors/env-invalid-variables/

export default defineConfig({
  adapter: cloudflare(),
  output: "server",
  site: "https://josef.dev",
  env: {
    schema: {
      SPOTIFY_CLIENT_ID: envField.string({
        access: "secret",
        context: "server",
        optional: true,
      }),
      SPOTIFY_CLIENT_SECRET: envField.string({
        access: "secret",
        context: "server",
        optional: true,
      }),
      SPOTIFY_REFRESH_TOKEN: envField.string({
        access: "secret",
        context: "server",
      }),
    },
    validateSecrets: true,
  },