Failed to exec deploy-storybook script

[jessepinuelas]

Describe the bug
No longer able to deploy to GH Pages. Previously I was able to simply run npm run deploy-storybook. Now when running the deploy command I run into the following error Failed to exec deploy-storybook script

To Reproduce

1. Run the following: npm run deploy-storybook

Expected behavior
Successfully deploys updates to GH Pages

System
OS: macOS 10.15.6
CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
Binaries:
Node: 12.12.0 - ~/.nvm/versions/node/v12.12.0/bin/node
npm: 6.11.3 - ~/.nvm/versions/node/v12.12.0/bin/npm
Browsers:
Chrome: 89.0.4389.90
Firefox: 86.0.1
Safari: 14.0
npmPackages:
@storybook/addon-actions: 6.1.21 => 6.1.21
@storybook/addon-essentials: 6.1.21 => 6.1.21
@storybook/addon-links: 6.1.21 => 6.1.21
@storybook/addons: 6.1.21 => 6.1.21
@storybook/node-logger: 6.1.21 => 6.1.21
@storybook/preset-create-react-app: 3.1.7 => 3.1.7
@storybook/react: 6.1.21 => 6.1.21
@storybook/storybook-deployer: 2.8.7 => 2.8.7
@storybook/theming: 6.1.21 => 6.1.21

Additional context
Have been successfully deploying story book to GH Pages for months now without any issues. In the last week or so deploying to GH Pages is no longer working.