Bump testcontainersVersion from 1.20.2 to 1.20.3 (#240)

Bumps `testcontainersVersion` from 1.20.2 to 1.20.3.

Updates `org.testcontainers:testcontainers` from 1.20.2 to 1.20.3
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.20.2...1.20.3)

Updates `org.testcontainers:postgresql` from 1.20.2 to 1.20.3
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.20.2...1.20.3)

---
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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

build.gradle.kts

@@ -31,7 +31,7 @@ val syfotjenesterVersion = "1.2020.07.02-07.44-62078cd74f7e"
 val helseXmlVersion = "1.0.4"
 val quartzSchedulerVersion = "2.3.2"
 val kotestTestContainersExtensionVersion = "2.0.2"
-val testcontainersVersion = "1.20.2"
+val testcontainersVersion = "1.20.3"
 
 val githubUser: String by project
 val githubPassword: String by project