Bump org.testcontainers:testcontainers from 1.19.8 to 1.20.4 (#100)

Bumps [org.testcontainers:testcontainers](https://github.com/testcontainers/testcontainers-java) from 1.19.8 to 1.20.4.
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.19.8...1.20.4)

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

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

build.gradle.kts

@@ -34,10 +34,10 @@ dependencies {
     // should use the -no-dependencies version, but logger configuration is broken in artifact
     // also would like to use newer version, but there is no working arm docker image available
     testImplementation("org.mock-server:mockserver-client-java:5.15.0")
-    testImplementation("org.testcontainers:testcontainers:1.19.8")
-    testImplementation("org.testcontainers:junit-jupiter:1.19.8")
-    testImplementation("org.testcontainers:mockserver:1.19.8")
-    testImplementation("org.testcontainers:hivemq:1.19.8")
+    testImplementation("org.testcontainers:testcontainers:1.20.4")
+    testImplementation("org.testcontainers:junit-jupiter:1.20.4")
+    testImplementation("org.testcontainers:mockserver:1.20.4")
+    testImplementation("org.testcontainers:hivemq:1.20.4")
     testImplementation("org.awaitility:awaitility-kotlin:4.2.1")
 }