Impact font not loaded on macos catalina

## Issue
I execute the sample text.js and the text in the rendered image didn't look like Impact font.

## Steps to Reproduce

In shell
```
cd
mkdir test-canvas
cd test-canvas
curl https://raw.githubusercontent.com/Automattic/node-canvas/master/examples/text.js > text.js
```
Edit text file to replace `var Canvas = require('..')` by `var Canvas = require('canvas')`
```
npm install canvas
node text.js
```

## Your Environment
* Version of node-canvas: canvas@2.6.1
* Environment : node 12.14.1, macOS 10.15.2

Start with examples/text.js and reproduce the reported output using canvas@2.6.1 on Node 12.14.1 and macOS 10.15.2. Compare the rendered sample with the expected Impact font, then verify that the sample renders Impact correctly after the issue is addressed.

Written by the indexing model from the issue text.