Build: Bump com.google.cloud:libraries-bom from 26.27.0 to 26.28.0 (#9258)

Bumps [com.google.cloud:libraries-bom](https://github.com/googleapis/java-cloud-bom) from 26.27.0 to 26.28.0.
- [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](https://github.com/googleapis/java-cloud-bom/compare/v26.27.0...v26.28.0)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index fc2fc60..1ddaccb 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -39,7 +39,7 @@
 flink116 = { strictly = "[1.16, 1.17[", prefer = "1.16.2"}
 flink117 = { strictly = "[1.17, 1.18[", prefer = "1.17.1"}
 flink118 =  { strictly = "[1.18, 1.19[", prefer = "1.18.0"}
-google-libraries-bom = "26.27.0"
+google-libraries-bom = "26.28.0"
 guava = "32.1.3-jre"
 hadoop2 = "2.7.3"
 hadoop3-client = "3.3.6"