Remove showLLMFeatures Flag

[Mephistic]

Summary

Now that the LLM features have been live for awhile, we should go back and remove the feature flag to simplify the code. The flag in question is: showLLMFeatures.

Success Criteria

• showLLMFeatures flag is removed from all referencing code, including the feature flags list
  • The LLM summaries and tags still appear in the Bill Details and Browse Bills pages