fix: The callback for AudioSource#allInstancesFinished never be called

[comus111]

Description

The callback for AudioSource#allInstancesFinished never be called.

Steps To Reproduce

final source = soloud.loadAsset('...');
source.allInstancesFinished.first.then(
  // The callback never be called
  (_) => soloud.disposeSound(source))
);
soloud.play(source);

Expected Behavior

// Should be called when playing is finished
(_) => soloud.disposeSound(source))

Additional Context

version: 3.3.7

[alnitak]

Hi @comus111, I've tried on Linux, Android, and Web, but I cannot reproduce the issue.

On which platform are you trying?