Problem

SDK should be using the latest tiktoken dependency. If I move to tiktoken 0.3.3, then I can't use the latest langchain-openai as it requires tiktoken >=0.5.2

Solution

rev the version. fixes #318

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

Test Plan

Ran the tests, checked the tiktoken docs for any breaking changes since 0.3.3 (there weren't any).