chore(issue-stream): Remove feature flag for issue stream refactor (#84442)

src/sentry/features/temporary.py

@@ -161,8 +161,6 @@ def register_temporary_features(manager: FeatureManager):
     manager.add("organizations:issue-search-snuba", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable issue stream table layout changes
     manager.add("organizations:issue-stream-table-layout", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
-    # When enabled, uses the functional issue stream component
-    manager.add("organizations:issue-stream-functional-refactor", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     manager.add("organizations:large-debug-files", OrganizationFeature, FeatureHandlerStrategy.INTERNAL, api_expose=False)
     manager.add("organizations:metric-issue-poc", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     manager.add("projects:metric-issue-creation", ProjectFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)