Generator tests: fix broken part-partof due to breaking dart_style changes

dart_style depends on analyzer 8. It seems using a dependency override
does not influence version solving of pub. But making analyzer an
explicit dependency does.

Follow-up to
3791870 Generator tests: fix broken part-partof due to breaking analyzer changes

Author: greenrobot-team

generator/integration-tests/part-partof/pubspec.yaml

@@ -17,12 +17,12 @@ dev_dependencies:
   build_test: '^2.1.3'
   io: '^1.0.4'
   path: '^1.8.3'
+  # analyzer 7.4.0 introduced breaking API changes in a minor release, breaking json_serializable
+  # https://github.com/google/json_serializable.dart/issues/1485
+  analyzer: '<=7.3.0'
 
 dependency_overrides:
   objectbox:
     path: ../../../objectbox
   objectbox_generator:
     path: ../../
-  # analyzer 7.4.0 introduced breaking API changes in a minor release, breaking json_serializable
-  # https://github.com/google/json_serializable.dart/issues/1485
-  analyzer: '<=7.3.0'