chore(deps): bump pydantic-ai-slim from 2.56.0 to 2.57.0 in /pydantic-ai

Bumps [pydantic-ai-slim](https://github.com/pydantic/pydantic-ai) from 2.56.0 to 2.57.0.
- [Release notes](https://github.com/pydantic/pydantic-ai/releases)
- [Changelog](https://github.com/pydantic/pydantic-ai/blob/main/docs/changelog.md)
- [Commits](pydantic/pydantic-ai@v2.56.0...v2.57.0)

---
updated-dependencies:
- dependency-name: pydantic-ai-slim
  dependency-version: 2.57.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pydantic-ai/pyproject.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 requires-python = ">=3.11"
 dependencies = [
     "aiohttp==3.14.5",
-    "pydantic-ai-slim[anthropic,openai]==2.56.0",
+    "pydantic-ai-slim[anthropic,openai]==2.57.0",
     "python-dotenv==1.2.4",
     "slack-bolt==1.30.0",
     "slack-cli-hooks==0.3.0",