Python: [Python] Updated Agents SDK version to latest for CopilotStudio connector

[tarockey]

Motivation and Context

Description

• Updated pyproject.toml to use the released packages for the Agents SDK.
• Updated imports in the copilot_studio_agent related files to use the new microsoft_agents namespace

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• [] I didn't break anyone 😄

[moonbox3]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
agents/copilot_studio
copilot_studio_agent.py	247	61	75%	89, 93–95, 99–102, 104, 110–111, 117, 122, 130–131, 135–137, 139–140, 143, 148, 151, 153, 179–180, 182–184, 234–236, 240–245, 288, 296, 298, 302, 305, 439, 488, 535, 541–542, 544, 546–547, 555, 557–559, 602–604, 612, 621, 644
copilot_studio_agent_settings.py	24	0	100%
TOTAL	27293	4560	83%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3759	23 💤	0 ❌	0 🔥	1m 50s ⏱️

[moonbox3]

Thanks so much for doing this!