Bump min w_flux version to pull in BatchedRedraw changes

pubspec.yaml

@@ -17,7 +17,7 @@ dependencies:
   source_span: "^1.4.0"
   transformer_utils: "^0.1.1"
   w_common: "^1.6.0"
-  w_flux: "^2.7.1"
+  w_flux: "^2.9.0"
   platform_detect: "^1.3.2"
   quiver: ">=0.21.4 <0.26.0"
 dev_dependencies:
@@ -37,11 +37,3 @@ transformers:
       $include: test/**_test{.*,}.dart
   # Reminder: dart2js should come after any other transformers that touch Dart code
   - $dart2js
-
-
-dependency_overrides:
-  w_flux:
-    git:
-      url: git@github.com:greglittlefield-wf/w_flux.git
-      ref: 189a1f97d95e0e3c446a5192c54e890fa61ebfb4 # from multiple_flux_redraws
-