Bump org.testcontainers:testcontainers-bom from 1.20.5 to 1.20.6

Bumps [org.testcontainers:testcontainers-bom](https://github.com/testcontainers/testcontainers-java) from 1.20.5 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@1.20.5...1.20.6)

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

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

Author: dependabot[bot]

dependencyManagement/build.gradle.kts

@@ -28,7 +28,7 @@ val DEPENDENCY_BOMS = listOf(
   "com.azure:azure-sdk-bom:1.2.31",
   "io.netty:netty-bom:4.1.119.Final",
   "org.junit:junit-bom:5.12.0",
-  "org.testcontainers:testcontainers-bom:1.20.5",
+  "org.testcontainers:testcontainers-bom:1.20.6",
 )
 
 val autoServiceVersion = "1.1.1"