Backport: fix(openai): skip passing reasoning items when using previous response id

[github-actions]

This is an automated backport of #15503 to the release-v6.0 branch. FYI @aayush-kapoor
This backport has conflicts that need to be resolved manually.

git cherry-pick output

Auto-merging packages/openai/src/responses/convert-to-openai-responses-input.test.ts
CONFLICT (content): Merge conflict in packages/openai/src/responses/convert-to-openai-responses-input.test.ts
Auto-merging packages/openai/src/responses/convert-to-openai-responses-input.ts
Auto-merging packages/openai/src/responses/openai-responses-language-model.test.ts
Auto-merging packages/openai/src/responses/openai-responses-language-model.ts
error: could not apply 17b559733... fix(openai): skip passing reasoning items when using previous response id (#15503)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"