Bump testContainersVersion from 1.20.2 to 1.20.3

Bumps `testContainersVersion` from 1.20.2 to 1.20.3.

Updates `org.testcontainers:testcontainers` from 1.20.2 to 1.20.3
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.20.2...1.20.3)

Updates `org.testcontainers:postgresql` from 1.20.2 to 1.20.3
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.20.2...1.20.3)

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

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

gradle/libs.versions.toml

@@ -17,7 +17,7 @@ logstashVersion = "7.4"
 logbackVersion = "1.5.11"
 kotestVersion = "5.9.1"
 mockkVersion = "1.13.13"
-testContainersVersion = "1.20.2"
+testContainersVersion = "1.20.3"
 mockOauth2ServerVersion = "2.1.9"
 micrometerVersion = "1.13.6"
 otelTargetSdkVersion = "1.43.0"