fix: Remove FUNCS and GPT 3.5 Turbo in examples

[Wendong-Fan]

Description

1. when importing FUNCS all toolkits would be initialized, which may cause errors due to missing API setting, user can make OpenAIFunction by them selves when needed, so we only need to keep toolkits
2. update gpt-3.5-turbo to gpt-4o-mini in examples, tutorial part would be updated in cookbook PRs

Motivation and Context

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of example)

Implemented Tasks

• Subtask 1
• Subtask 2
• Subtask 3

Checklist

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• My change requires a change to the documentation.
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• I have updated the documentation accordingly.

[WHALEEYE]

LGTM, but I think the overall style of our toolkits is quite chaotic, may need to be refactored later

[Wendong-Fan]

LGTM, but I think the overall style of our toolkits is quite chaotic, may need to be refactored later

I will merge this PR first to solve the issue caused by toolkits api requirement, we can do further enhancement later