registerFont() not parsing the font.

## Issue

## Steps to Reproduce

I want to use the Roboto font, but if i try to register the font via `registerFont()` , the code ends with error. `Could not parse font file`
```js
const { createCanvas, registerFont } = require("canvas");
registerFont("./cdn/roboto.ttf", {
family: "Roboto",
});
const canvas = createCanvas(500, 500);
const ctx = canvas.getContext("2d");
```

## Environment
* Version of node-canvas : `2.8.0`
* Environment : `node 16.4.0`