Error When Using Fixed ESBuild Version

Attempts to use a stable version with `let esbuild = SwiftyESBuild(version: .fixed("0.19.11"))` fail with the following error message:

```
The payload returned by https://registry.npmjs.org/@esbuild/{os}-{arch} doesn't contain the version v0.19.11
```

SwiftyESBuild version: 0.3.0