docs: remove todo

docs/migration/v12.md

@@ -74,7 +74,7 @@ In terms of the React 18-related changes, upgrading to `@dhis2/cli-app-scripts`
 
 ### Default props
 
-The main change in React 18 that is expected to affect apps at runtime is that using `MyComponent.defaultProps = { ... }` is deprecated [todo: just for functional components?], and will be removed in the next version. While non-breaking, this change comes along with warning messages in the console for every rendered component that uses them, which can be chatty and annoying.
+The main change in React 18 that is expected to affect apps at runtime is that using `MyComponent.defaultProps = { ... }` is deprecated, and will be removed in the next major version. While non-breaking, this change comes along with warning messages in the console for every rendered component that uses them, which can be chatty and annoying.
 
 The fix is to move prop defaults -- either to default parameters for functional components, or to a static property for class components. This code mod can help with the migration, and was used for the `@dhis2/ui` library: [transform.js](https://gist.github.com/kabaros/45ed16660ac89dc48d22e03836b1e981)