Update setup-node GitHub action
Update setup-node GitHub action

The build isn't working because apparently there was a minor security vulnerability in setting the path with the old action (I think).

Here's the failure: https://github.com/austinjavascript/austinjavascript.com/runs/2278717518?check_suite_focus=true
austinjavascript/austinjavascript.github.io,austinjavascript/austinjavascript.github.io,austinjavascript/austinjavascript.github.io,austinjavascript/austinjavascript.github.io,austinjavascript/austinjavascript.github.io