chore: update to Electron 33.3.0

[dsanders11]

Required fixing the types in a test, I believe due to the change upstream in electron/typescript-definitions#273. Since app.on is overloaded, TypeScript ends up choosing the last signature, which used to be Function before that change (fully permissive when invoking), after which it became () => void. Unfortunately it appears there's no way to extract the callback signature of just the events we want, so I manually rolled the types to get this building cleanly again.

When inferring from a type with multiple call signatures (such as the type of an overloaded function), inferences are made from the last signature (which, presumably, is the most permissive catch-all case). It is not possible to perform overload resolution based on a list of argument types.

[coveralls]

coverage: 87.597%. remained the same
when pulling 2845388 on chore/bump-electron-33
into 4d7f807 on main.