Python: Add streaming support for code interpreter deltas

[giles17]

Motivation and Context

Adds handlers for code interpreter streaming events so that code snippets are surfaced in the Contents collection during streaming.
Contributes to #3683 (Python side)

Description

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/core/agent_framework/openai
_responses_client.py	573	62	89%	279–280, 285, 316, 324, 347, 409, 441, 466, 472, 490–491, 513, 518, 574, 588, 605, 618, 673, 752, 757, 761–763, 767–768, 791, 860, 882–883, 898–899, 917–918, 1049–1050, 1066, 1068, 1143–1151, 1243, 1298, 1313, 1349–1350, 1352–1354, 1368–1370, 1380–1381, 1387, 1402
TOTAL	16617	2059	87%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3932	225 💤	0 ❌	0 🔥	1m 8s ⏱️

[Copilot]

Pull request overview

Adds Python-side streaming support for OpenAI Responses API code interpreter code delta/done events so code snippets appear in ChatResponseUpdate.contents during streaming (addressing #3683).

Changes:

• Handle response.code_interpreter_call_code.delta and response.code_interpreter_call_code.done in _parse_chunk_from_openai() by emitting code_interpreter_tool_call content.
• Add unit tests covering parsing of these new streaming event types.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
python/packages/core/agent_framework/openai/_responses_client.py	Adds parsing for code interpreter code delta/done stream events into Content.from_code_interpreter_tool_call(...).
python/packages/core/tests/openai/test_openai_responses_client.py	Adds tests ensuring delta/done events produce code_interpreter_tool_call contents with text inputs.