Describe the bug

When using an Image Substitutor (either image.substitutor in ~/.testcontainer.properties or Env TESTCONTAINERS_IMAGE_SUBSTITUTOR, see here) for test-containers, the kubernetes client configuration may not detect the kubernetes-client-config will fail.

Expected behavior

Kubernetes configuration is created based on the requested service.

Actual behavior

RuntimeException is thrown.

How to Reproduce?

1. Create a class implementing org.testcontainers.utility.ImageNameSubstitutor, replacing the e.g. the registry for kube-api.
2. One of
   1. Set EnvVar TESTCONTAINERS_IMAGE_SUBSTITUTOR to the class' name
   2. Create file or add line in ~/.testcontainers.properties image.substitutor= pointing to the class' name
3. @Inject the KubernetesClient in your test

Output of uname -a or ver

Darwin 23.2.0 Darwin Kernel Version 23.2.0: Wed Nov 15 21:54:10 PST 2023; root:xnu-10002.61.3~2/RELEASE_X86_64 x86_64

Output of java -version

openjdk version "19.0.2" 2023-01-17

Quarkus version or git rev

3.6.4

Build tool (ie. output of mvnw --version or gradlew --version)

Gradle 8.5

Additional information

No response