Bump org.testcontainers:testcontainers from 1.19.1 to 1.20.3

Bumps [org.testcontainers:testcontainers](https://github.com/testcontainers/testcontainers-java) from 1.19.1 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@1.19.1...1.20.3)

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

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

build.gradle.kts

@@ -48,7 +48,7 @@ subprojects {
 
     extra.apply {
         set("creekVersion", "0.4.2-SNAPSHOT")
-        set("testContainersVersion", "1.19.1")  // https://mvnrepository.com/artifact/org.testcontainers/testcontainers
+        set("testContainersVersion", "1.20.3")  // https://mvnrepository.com/artifact/org.testcontainers/testcontainers
         set("spotBugsVersion", "4.8.6")         // https://mvnrepository.com/artifact/com.github.spotbugs/spotbugs-annotations
         set("jacksonVersion", "2.18.1")         // https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations
         set("picocliVersion", "4.7.6")          // https://mvnrepository.com/artifact/info.picocli/picocli