checkup-plugin-ember is incompatible with ember-template-lint 4.0 & eslint v8

[runspired]

These projects have unfortunately moved to ESM already :)

[scalvert]

Yep, I'm aware. I have a branch that converts checkup to esm, and it's very straightforward to convert. The only thing that prevented my converting things fully at the time was the lack of support in jest/ts-jest. That said, I've been experimenting with converting to vitest, which uses esm by default as it uses vite under the covers. This looks promising, and may provide us a nice path to convert.

cc/ @rwjblue for thoughts.