Upgrade to ESLint 8

[SleeplessByte]

This upgrades the entire track to ESLint 8.

If you're having trouble locally (when contributing) with an eslint plugin (like in VS Code) and you've already:

• tried turning it off and on again
• tried re-installing it (to force the latest version)

Run the following:

rm -rf node_modules
npm i

[junedev]

CI wasn't triggered here again (so it does not seem to be related to the format action), will close and open.