deps(deps): bump google-genai from 2.17.0 to 2.18.1 (#1163)

Bumps [google-genai](https://github.com/googleapis/python-genai) from 2.17.0 to 2.18.1.
- [Release notes](https://github.com/googleapis/python-genai/releases)
- [Changelog](https://github.com/googleapis/python-genai/blob/main/CHANGELOG.md)
- [Commits](https://github.com/googleapis/python-genai/compare/v2.17.0...v2.18.1)

---
updated-dependencies:
- dependency-name: google-genai
  dependency-version: 2.18.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements-ci.txt

@@ -1731,9 +1731,9 @@ google-crc32c==1.8.0 \
     # via
     #   google-cloud-storage
     #   google-resumable-media
-google-genai==2.17.0 \
-    --hash=sha256:6b640a2390c82b4a240873eddb9f518c6d2c33244b2de16ed3d14526a6da7f57 \
-    --hash=sha256:a4835563c60aee646c9c4b261c507aa4a624710d25017012d20dc65abf3d9a54
+google-genai==2.18.1 \
+    --hash=sha256:36a5949233e64a60f6cc4521bff7a76b7c569d0aa227bbe9fa642213b8a3a3b2 \
+    --hash=sha256:a1e2be75c16234adc6641afd1ad4dd44218c9eec005d938bdc428585a048918a
     # via semantica (pyproject.toml)
 google-resumable-media==2.10.1 \
     --hash=sha256:224975032ddb73f7ed9e2f0f4cc08ed1b06874c52d48cc8533e3eb72980b21a0 \