deps: bump testcontainers-bom from 1.18.1 to 1.18.3 (#1915)

Bumps [testcontainers-bom](https://github.com/testcontainers/testcontainers-java) from 1.18.1 to 1.18.3.
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.18.1...1.18.3)

---
updated-dependencies:
- dependency-name: org.testcontainers:testcontainers-bom
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

spring-cloud-gcp-samples/pom.xml

@@ -24,7 +24,7 @@
 		<!-- Dependency versions -->
 		<spring-native.version>0.12.2</spring-native.version>
 		<google-cloud-graalvm-support.version>0.7.0</google-cloud-graalvm-support.version>
-		<testcontainers.version>1.18.1</testcontainers.version>
+		<testcontainers.version>1.18.3</testcontainers.version>
 
 		<!-- Checkstyle versions. Keep in sync with ../pom.xml -->
 		<maven-checkstyle-plugin.version>3.2.2</maven-checkstyle-plugin.version>