Bump org.testcontainers:testcontainers from 1.20.5 to 1.20.6

Bumps [org.testcontainers:testcontainers](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
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

build.gradle.kts

@@ -21,7 +21,7 @@ dependencies {
 
     testImplementation("junit:junit:4.13.2")
     testImplementation("org.hamcrest:hamcrest:3.0")
-    testImplementation("org.testcontainers:testcontainers:1.20.5")
+    testImplementation("org.testcontainers:testcontainers:1.20.6")
 }
 
 group = "art.iculate.flume"