Bump org.assertj:assertj-core from 3.27.4 to 3.27.6 in /modules/gcloud

Bumps [org.assertj:assertj-core](https://github.com/assertj/assertj) from 3.27.4 to 3.27.6.
- [Release notes](https://github.com/assertj/assertj/releases)
- [Commits](assertj/assertj@assertj-build-3.27.4...assertj-build-3.27.6)

---
updated-dependencies:
- dependency-name: org.assertj:assertj-core
  dependency-version: 3.27.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

modules/gcloud/build.gradle

@@ -13,7 +13,7 @@ dependencies {
     testImplementation 'com.google.cloud:google-cloud-pubsub'
     testImplementation 'com.google.cloud:google-cloud-spanner'
     testImplementation 'com.google.cloud:google-cloud-bigtable'
-    testImplementation 'org.assertj:assertj-core:3.27.4'
+    testImplementation 'org.assertj:assertj-core:3.27.6'
 }
 
 test {