Bump com.google.api-client:google-api-client in /plugins/discovery-gce

Bumps [com.google.api-client:google-api-client](https://github.com/googleapis/google-api-java-client) from 1.35.2 to 2.6.0.
- [Release notes](https://github.com/googleapis/google-api-java-client/releases)
- [Changelog](https://github.com/googleapis/google-api-java-client/blob/main/CHANGELOG.md)
- [Commits](googleapis/google-api-java-client@v1.35.2...v2.6.0)

---
updated-dependencies:
- dependency-name: com.google.api-client:google-api-client
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

plugins/discovery-gce/build.gradle

@@ -19,7 +19,7 @@ opensearchplugin {
 
 dependencies {
   api "com.google.apis:google-api-services-compute:v1-rev20240407-2.0.0"
-  api "com.google.api-client:google-api-client:1.35.2"
+  api "com.google.api-client:google-api-client:2.6.0"
   api "com.google.oauth-client:google-oauth-client:1.35.0"
   api "com.google.http-client:google-http-client:${versions.google_http_client}"
   api "com.google.http-client:google-http-client-gson:${versions.google_http_client}"