Bump pytest from 9.0.2 to 9.0.3 in /python/packages/ag-ui (#5461)

* Bump pytest from 9.0.2 to 9.0.3 in /python/packages/ag-ui

Bumps [pytest](https://github.com/pytest-dev/pytest) from 9.0.2 to 9.0.3.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@9.0.2...9.0.3)

---
updated-dependencies:
- dependency-name: pytest
  dependency-version: 9.0.3
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

* Fix CI: bump pytest to 9.0.3 across all workspace packages and update uv.lock

Agent-Logs-Url: https://github.com/microsoft/agent-framework/sessions/a9996d8b-3fb7-436b-a22f-f4a8c436b213

Co-authored-by: moonbox3 <35585003+moonbox3@users.noreply.github.com>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: moonbox3 <35585003+moonbox3@users.noreply.github.com>

Author: 3 people