⬆️ Bump google.golang.org/genai from 1.50.0 to 1.51.0

Bumps [google.golang.org/genai](https://github.com/googleapis/go-genai) from 1.50.0 to 1.51.0.
- [Release notes](https://github.com/googleapis/go-genai/releases)
- [Changelog](https://github.com/googleapis/go-genai/blob/main/CHANGELOG.md)
- [Commits](googleapis/go-genai@v1.50.0...v1.51.0)

---
updated-dependencies:
- dependency-name: google.golang.org/genai
  dependency-version: 1.51.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

go.mod

@@ -74,7 +74,7 @@ require (
 	golang.org/x/text v0.35.0 // indirect
 	google.golang.org/adk v1.0.0
 	google.golang.org/api v0.272.0
-	google.golang.org/genai v1.50.0
+	google.golang.org/genai v1.51.0
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/yaml.v3 v3.0.1
 )

go.sum

@@ -149,8 +149,8 @@ google.golang.org/adk v1.0.0 h1:DcJGKH9YweOdsAvE5Hu9UhhLoVYcNEVKzvOPS+B49lQ=
 google.golang.org/adk v1.0.0/go.mod h1:wLmpRAp0zXcrdUN2V6mNoh+mj/4O16k0YzGJMNF7Mjk=
 google.golang.org/api v0.272.0 h1:eLUQZGnAS3OHn31URRf9sAmRk3w2JjMx37d2k8AjJmA=
 google.golang.org/api v0.272.0/go.mod h1:wKjowi5LNJc5qarNvDCvNQBn3rVK8nSy6jg2SwRwzIA=
-google.golang.org/genai v1.50.0 h1:yHKV/vjoeN9PJ3iF0ur4cBZco4N3Kl7j09rMq7XSoWk=
-google.golang.org/genai v1.50.0/go.mod h1:A3kkl0nyBjyFlNjgxIwKq70julKbIxpSxqKO5gw/gmk=
+google.golang.org/genai v1.51.0 h1:IZGuUqgfx40INv3hLFGCbOSGp0qFqm7LVmDghzNIYqg=
+google.golang.org/genai v1.51.0/go.mod h1:A3kkl0nyBjyFlNjgxIwKq70julKbIxpSxqKO5gw/gmk=
 google.golang.org/genproto v0.0.0-20260217215200-42d3e9bedb6d h1:vsOm753cOAMkt76efriTCDKjpCbK18XGHMJHo0JUKhc=
 google.golang.org/genproto v0.0.0-20260217215200-42d3e9bedb6d/go.mod h1:0oz9d7g9QLSdv9/lgbIjowW1JoxMbxmBVNe8i6tORJI=
 google.golang.org/genproto/googleapis/api v0.0.0-20260226221140-a57be14db171 h1:tu/dtnW1o3wfaxCOjSLn5IRX4YDcJrtlpzYkhHhGaC4=