wait until the last minute to load sounds

[aaron13100]

Checklist

• run pnpm format
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

Feel free to reject this or change it. It's untested as I can't get the project to build/compile. On my JavaScript version I had to separate out the initialization of audioContext in order for the sound to work on the first firework, like this.

  init() {
    if (this.audioContext == null) {
      this.audioContext = new (window.AudioContext || window.webkitAudioContext)();
      this.loadSounds();
    }
    if (!this.onInit && this.isEnabled) {
      this.onInit = true;
    }
  }

but it looks like what I committed in typescript will work.