build(deps): bump com.google.cloud:google-cloud-shared-config

Bumps [com.google.cloud:google-cloud-shared-config](https://github.com/googleapis/java-shared-config) from 1.12.2 to 1.12.3.
- [Release notes](https://github.com/googleapis/java-shared-config/releases)
- [Changelog](https://github.com/googleapis/java-shared-config/blob/main/CHANGELOG.md)
- [Commits](googleapis/java-shared-config@v1.12.2...v1.12.3)

---
updated-dependencies:
- dependency-name: com.google.cloud:google-cloud-shared-config
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

samples/java/liquibase/pom.xml

@@ -37,7 +37,7 @@
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-shared-config</artifactId>
-    <version>1.12.2</version>
+    <version>1.12.3</version>
   </parent>
   <scm>
     <connection>scm:git:[email protected]:GoogleCloudPlatform/pgadapter.git</connection>