deepseek: Update DeepSeek Flash to V4.1 (#64014)

# Objective

deepseek API: https://api-docs.deepseek.com/updates/

## Solution

deepseek rename deepseek v4 flash to deepseek flash



https://github.com/user-attachments/assets/72c473c9-a4bf-49e0-a7d6-0217a6dcc65b


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Release Notes:

- agent: Added support for DeepSeek Flash 4.1

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Signed-off-by: Xiaobo Liu <cppcoffee@gmail.com>
Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: Bennet Bo Fenner <bennet@zed.dev>
53fcf4be37Xiaobo Liu committed on 9/16/2026, 9:49:13 AM· committed by GitHubparentfe1dd2d
4 files changedLine totals unavailable