[Blog] Add note on ES2023

docs/blog/version-5.0-release-notes.md

@@ -16,9 +16,20 @@ Version 5.0 of [Foal](https://foalts.org/) is out!
 
 ## Supported versions of Node and TypeScript
 
-- Support for Node 18 has been dropped and support for Node 22 has been added.
+- Support for Node 18 has been dropped and support for Node 22 has been added. Foal code is now compiled to ES2023.
 - The supported version of TypeScript is version 5. Update your `package.json` file accordingly.
 
+> If you're using the `GraphQLController` with the `resolvers` property, you need to add the `declare` keyword before the property name:
+> ```typescript
+> 
+> export class ApiController extends GraphQLController {
+>   schema = // ...
+>
+>   @dependency
+>   declare resolvers: RootResolverService;
+> }
+> ```
+
 ## Better typing
 
 - The default type of `Context.state` is now `{}`. This way, you'll get a compilation error if you forget to specify a type for the state.