build(deps): bump org.testcontainers:testcontainers

Bumps [org.testcontainers:testcontainers](https://github.com/testcontainers/testcontainers-java) from 1.20.1 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@1.20.1...1.20.3)

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

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

gradle/libs.versions.toml

@@ -6,7 +6,7 @@ slf4j = "2.0.16"
 guava = "33.3.1-jre"
 assertj = "3.26.3"
 junit = "5.11.3"
-testcontainers = "1.20.1"
+testcontainers = "1.20.3"
 protoc = "3.25.1"
 failsafe = "3.3.2"
 awaitility = "4.2.2"