Bump testcontainersVersion from 1.19.4 to 1.19.6

Bumps `testcontainersVersion` from 1.19.4 to 1.19.6.

Updates `org.testcontainers:junit-jupiter` from 1.19.4 to 1.19.6
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.19.4...1.19.6)

Updates `org.testcontainers:kafka` from 1.19.4 to 1.19.6
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.19.4...1.19.6)

Updates `org.testcontainers:testcontainers` from 1.19.4 to 1.19.6
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.19.4...1.19.6)

Updates `org.testcontainers:postgresql` from 1.19.4 to 1.19.6
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.19.4...1.19.6)

---
updated-dependencies:
- dependency-name: org.testcontainers:junit-jupiter
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.testcontainers:kafka
  dependency-type: direct:production
  update-type: version-update:semver-patch
- 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]>

build.gradle

@@ -122,7 +122,7 @@ ext {
     jupiterVersion = "5.10.1"
     jettyVersion = "11.0.15"
     servletVersion = "4.0.1"
-    testcontainersVersion = '1.19.4'
+    testcontainersVersion = '1.19.6'
     awaitilityVersion = '4.2.0'
     jupiterVersion = "5.9.1"
     log4jVersion = "2.20.0"