add github model as model provider

[yongjer]

Self Checks

• [X] I have searched for existing issues search for existing issues, including closed ones.
• [X] I confirm that I am using English to submit this report (我已阅读并同意 Language Policy).
• [X] [FOR CHINESE USERS] 请务必使用英文提交 Issue，否则会被关闭。谢谢！:）
• [X] Please do not modify this template :) and fill in all the required fields.

1. Is this request related to a challenge you're experiencing? Tell me about your story.

none

2. Additional context or comments

No response

3. Can you help us with this feature?

• [ ] I am interested in contributing to this feature.

[dosubot[bot]]

Hi, @yongjer. I'm Dosu, and I'm helping the Dify team manage their backlog. I'm marking this issue as stale.

Issue Summary:

• Request to add a GitHub model as a model provider.
• No specific details or challenges provided.
• No further comments or activity since the issue was opened.

Next Steps:

• Please let us know if this issue is still relevant to the latest version of Dify by commenting here.
• If there is no further activity, the issue will be automatically closed in 15 days.

Thank you for your understanding and contribution!