Bump @google/genai from 1.50.1 to 2.4.0

Bumps [@google/genai](https://github.com/googleapis/js-genai) from 1.50.1 to 2.4.0.
- [Release notes](https://github.com/googleapis/js-genai/releases)
- [Changelog](https://github.com/googleapis/js-genai/blob/main/CHANGELOG.md)
- [Commits](https://github.com/googleapis/js-genai/compare/v1.50.1...v2.4.0)

---
updated-dependencies:
- dependency-name: "@google/genai"
  dependency-version: 2.4.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

package.json

@@ -8,7 +8,7 @@
     "bun:start": "bun run dist/index.js"
   },
   "dependencies": {
-    "@google/genai": "^1.50.1",
+    "@google/genai": "^2.4.0",
     "@libsql/client": "^0.17.3",
     "@mistralai/mistralai": "^1.15.1",
     "@napi-rs/canvas": "^0.1.100",