Python: Bump prek from 0.3.8 to 0.3.9 in /python (#5228)

* Bump prek from 0.3.8 to 0.3.9 in /python

Bumps [prek](https://github.com/j178/prek) from 0.3.8 to 0.3.9.
- [Release notes](https://github.com/j178/prek/releases)
- [Changelog](https://github.com/j178/prek/blob/master/CHANGELOG.md)
- [Commits](https://github.com/j178/prek/compare/v0.3.8...v0.3.9)

---
updated-dependencies:
- dependency-name: prek
  dependency-version: 0.3.9
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

* Fix CI: bump prek to 0.3.9 in lab package and update uv.lock

Agent-Logs-Url: https://github.com/microsoft/agent-framework/sessions/f17751e5-c5a8-4d42-9555-6bf708a2ef47

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>

python/packages/lab/pyproject.toml

@@ -69,7 +69,7 @@ dev = [
     "tomli-w==1.2.0",
     # tau2 from source (not available on PyPI)
     "tau2@ git+https://github.com/sierra-research/tau2-bench@5ba9e3e56db57c5e4114bf7f901291f09b2c5619",
-    "prek==0.3.8",
+    "prek==0.3.9",
 ]
 
 [project.scripts]