Bump org.testcontainers:testcontainers-bom from 1.19.3 to 1.20.6

Bumps [org.testcontainers:testcontainers-bom](https://github.com/testcontainers/testcontainers-java) from 1.19.3 to 1.20.6.
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.19.3...1.20.6)

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

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

Author: dependabot[bot]

dependencyManagement/build.gradle.kts

@@ -44,7 +44,7 @@ val dependencyBoms = listOf(
   "org.apache.logging.log4j:log4j-bom:2.21.1",
   "org.junit:junit-bom:5.10.1",
   "org.springframework.boot:spring-boot-dependencies:2.7.17",
-  "org.testcontainers:testcontainers-bom:1.19.3",
+  "org.testcontainers:testcontainers-bom:1.20.6",
   "software.amazon.awssdk:bom:2.21.33",
 )