build(deps): bump testcontainers from 1.20.5 to 1.20.6

Bumps `testcontainers` from 1.20.5 to 1.20.6.

Updates `org.testcontainers:testcontainers` 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)

Updates `org.testcontainers:postgresql` 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
- dependency-name: org.testcontainers:postgresql
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -41,7 +41,7 @@ detekt = "1.23.8"
 xmlunit = "2.10.0"
 kotest = "5.9.1"
 reaktive = "2.2.0"
-testcontainers = "1.20.5"
+testcontainers = "1.20.6"
 keycloak = "26.0.4"
 
 [libraries]