remove checklist item that should be caught by TypeScript

checklists/code-review-checklist.md

@@ -373,7 +373,6 @@ This section may be omitted if the sim has not been instrumented for PhET-iO, bu
   determining whether `toStateObject` should use `null` or `undefined` values.
 - [ ] PhET prefers to use the term "position" to refer to the physical (x,y) position of objects. This applies to both
   brands, but is more important for the PhET-iO API. See https://github.com/phetsims/phet-info/issues/126
-- [ ] Are your IOType state methods violating the API of the core type by accessing private fields?
 - [ ] When defining a boolean Property to indicate whether something is enabled with a tandem name of `enabledProperty`,
   use `AXON/EnabledProperty`. This should be done in both the model and the view. If you're using a DerivedProperty,
   skip this item.