Bump com.google.cloud:libraries-bom in /modules/gcloud

Bumps [com.google.cloud:libraries-bom](https://github.com/googleapis/java-cloud-bom) from 26.66.0 to 26.69.0.
- [Release notes](https://github.com/googleapis/java-cloud-bom/releases)
- [Changelog](https://github.com/googleapis/java-cloud-bom/blob/main/release-please-config.json)
- [Commits](googleapis/java-cloud-bom@v26.66.0...v26.69.0)

---
updated-dependencies:
- dependency-name: com.google.cloud:libraries-bom
  dependency-version: 26.69.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

modules/gcloud/build.gradle

@@ -6,7 +6,7 @@ dependencies {
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher:1.11.0'
 
     testImplementation 'org.junit.jupiter:junit-jupiter:5.13.4'
-    testImplementation platform("com.google.cloud:libraries-bom:26.66.0")
+    testImplementation platform("com.google.cloud:libraries-bom:26.69.0")
     testImplementation 'com.google.cloud:google-cloud-bigquery'
     testImplementation 'com.google.cloud:google-cloud-datastore'
     testImplementation 'com.google.cloud:google-cloud-firestore'