`it.todo()` in tests should be a CI failure

[turt2live]

these seemingly got missed in code review - 2 of them snuck into our tests already.

[MadLittleMods]

eslint-plugin-jest has been introduced into the codebases but I don't see a specific rule for this. Perhaps would be a good to create an issue over there to see if it materializes by the time we get to this.

The presence of it.todo() seems better to remember what to implement than just leaving them out. But its understandable to also nudge people to finish their testing coverage in their PR.

There is a related prefer-todo which makes sense on its own but is different than what this issue wants to do.