build(deps): bump ruff from 0.15.2 to 0.15.4 in /claude-agent-sdk

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.15.2 to 0.15.4.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.15.2...0.15.4)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.15.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

claude-agent-sdk/pyproject.toml

@@ -14,7 +14,7 @@ dependencies = [
 [project.optional-dependencies]
 dev = [
     "pytest",
-    "ruff==0.15.2",
+    "ruff==0.15.4",
 ]
 
 [tool.setuptools.packages.find]