fix (grouping): Fix feature flag config for split enhancements (#91468)

`FeatureHandlerStrategy.INTERNAL` isn't flagpole. Whoops.

Author: lobsterkatie

src/sentry/features/temporary.py

@@ -330,7 +330,7 @@ def register_temporary_features(manager: FeatureManager):
     # Lets organizations manage grouping configs
     manager.add("organizations:set-grouping-config", OrganizationFeature, FeatureHandlerStrategy.INTERNAL, api_expose=True)
     # Enable the split enhancements experiment
-    manager.add("organizations:run-split-enhancements", OrganizationFeature, FeatureHandlerStrategy.INTERNAL, api_expose=False)
+    manager.add("organizations:run-split-enhancements", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable SAML2 Single-logout
     manager.add("organizations:sso-saml2-slo", OrganizationFeature, FeatureHandlerStrategy.OPTIONS, api_expose=False)
     # Show links and upsells to Insights modules