chore(deps): update dependency riverpod_generator to v4

Author: renovate[bot]

pubspec.yaml

@@ -74,7 +74,7 @@ dev_dependencies:
   freezed_lint: ^0.0.9
   json_serializable: ^6.9.5
   mocktail: ^1.0.4
-  riverpod_generator: ^2.6.5
+  riverpod_generator: 4.0.0+1
   riverpod_lint: ^2.6.5
   very_good_analysis: ^8.0.0-rc.1
   very_good_cli: ^0.25.0