Remove use of `EmptyObject` type

[bertdeblock]

Taken from Glint's docs:

• If no Args key is specified, it will be a type error to pass any arguments to your component.
• If no Blocks key is specified, it will be a type error to invoke your component in block form.

Which means we can simply omit Args and Blocks instead of using the EmptyObject type.

Also, it seems that the EmptyObject type is private:
https://github.com/DefinitelyTyped/DefinitelyTyped/blob/7a577c63b4fee486d2fe01566ab52865b8490b80/types/ember__component/helper.d.ts#L9-L25

[lukemelia]

Ah, good to know!