This PR turns the `eslint no-undef` rule back on because it's dangerous to have it turned off 😈
This resulted in `eslint` complaining about various global variables, such as `window` (`env: browser`), `cy` (`env: cypress`), and `describe` (`env: mocha`). I added the appropriate `.eslintrc`s and `env` entries to set `env` as appropriate, and removed these imports from tests because they are unnecessary. Also fixed ~10 bugs 🐛 from valid `no-undef` errors. @kristw @mistercrunch @michellethomas @graceguo-supercat [ Full content available at: https://github.com/apache/incubator-superset/pull/5879 ] This message was relayed via gitbox.apache.org for devnull@infra.apache.org
