feat(runapi): add RunStepList response args

[Ccheers]

A similar PR may already be submitted!
Please search among the Pull request before creating one.

If your changes introduce breaking changes, please prefix the title of your pull request with "[BREAKING_CHANGES]". This allows for clear identification of such changes in the 'What's Changed' section on the release page, making it developer-friendly.

Thanks for submitting a pull request! Please provide enough information so that others can review your pull request.

Describe the change
add RunStepList response args

type RunStepList struct {
	...

	FirstID string `json:"first_id"`
	LastID  string `json:"last_id"`
	HasMore bool   `json:"has_more"`

	...
}

Describe your solution
ref: https://platform.openai.com/docs/api-reference/runs/listRunSteps

Tests
Briefly describe how you have tested these changes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (515de02) 98.35% compared to head (81a97b0) 98.35%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #573   +/-   ##
=======================================
  Coverage   98.35%   98.35%           
=======================================
  Files          24       24           
  Lines        1276     1276           
=======================================
  Hits         1255     1255           
  Misses         15       15           
  Partials        6        6           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[sashabaranov]

thanks!