Update project paperjs to v0.9.21

libgrabber updated project paperjs to v0.9.21.

@paperjs

### Metadata information

```json
{
  "metadata": {
    "packageManager": "github",
    "name": "paperjs",
    "repo": "paperjs/paper.js",
    "files": {
      "basePath": "dist/",
      "include": ["*.js"],
      "exclude": []
    },
    "path": "/home/jsdelivr/files/paperjs",
    "localVersions": ["0.9.7", "0.9.11", "0.9.15", "0.9.18", "0.9.19", "0.9.20"],
    "remoteVersions": ["v0.1.0", "v0.2.0", "v0.2.1", "v0.2.2", "v0.8.0", "v0.8.1", "v0.8.2", "v0.8.3", "v0.9.0", "v0.9.1", "v0.9.2", "v0.9.3", "v0.9.4", "v0.9.5", "v0.9.6", "v0.9.7", "v0.9.8", "v0.9.9", "v0.9.10", "v0.9.11", "v0.9.12", "v0.9.13", "v0.9.14", "v0.9.15", "v0.9.16", "v0.9.17", "v0.9.18", "v0.9.19", "v0.9.20", "v0.9.21"],
    "branchVersions": []
  },
  "version": "v0.9.21",
  "updated": true,
  "updatePath": "/home/jsdelivr/files/paperjs/0.9.21",
  "branch": "paperjs/v0.9.21"
}
```