[Model] add Step-3.7-Flash (#492)

Signed-off-by: luotingdan <luotingdan@stepfun.com>
Signed-off-by: ltd0924 <32387785+ltd0924@users.noreply.github.com>
Signed-off-by: Jee Jee Li <jeejeelee@inferact.ai>
Co-authored-by: luotingdan <luotingdan@stepfun.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Jee Jee Li <jeejeelee@inferact.ai>