fix(langfuse): Handle null usage values to prevent validation errors#16396

krrishdholakia merged 2 commits intoBerriAI:mainBerriAI/litellm:mainfrom

AlanPonnachan:fix/langfuse-null-usage-validationAlanPonnachan/litellm:fix/langfuse-null-usage-validationCopy head branch name to clipboard