Add kubetest4j to testing frameworks list

[kornys]

Adds kubetest4j to Testing > Integration.

Disclosure: I am the author of this tool.

Why it qualifies (criterion d — a niche product filling a gap): it is the only Java testing library purpose-built for Kubernetes and OpenShift that provides
declarative, annotation-based resource lifecycle management with JUnit integration. It fills the gap between generic container testing (TestContainers) and manual
Fabric8 client setup.

Distinction from similar entries already listed:

• Arquillian — designed for Java EE container testing (WildFly, Payara, Tomcat). kubetest4j targets Kubernetes/OpenShift clusters directly, managing native K8s
  resources (Deployments, Services, Operators) with automatic LIFO cleanup.
• Citrus — focuses on message-based integration testing (HTTP, JMS, Kafka). kubetest4j focuses on Kubernetes resource lifecycle, namespace management, and pod
  log collection.
• Hoverfly Java — simulates HTTP services via proxy. kubetest4j tests against real Kubernetes clusters, not simulated services.

Developer-friendliness requirements:

• Open source, Apache-2.0 licensed.
• Published to Maven Central under io.skodjob.kubetest4j.
• Used in production by Strimzi, Debezium, OpenDataHub, and StreamsHub.
• Documentation in English with quickstart guide, module READMEs, and comparison with alternatives.
• OpenSSF Best Practices Silver badge.

Entry is alphabetically sorted and follows the required format.

Suggestion type

• Project
• Resource

Checklist

• I searched the list and existing issues for duplicates.
• I changed README_SOURCE.md, not the generated README.md.
• This pull request contains one suggestion.
• The suggestion is relevant to Java or the JVM and fits its chosen category.
• I used the canonical project or resource link.
• The suggestion is current and maintained.
• The concise, neutral description explains its distinguishing value and ends with punctuation.
• Licensing is clear and any restrictive terms are disclosed where applicable.

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Summary by cubic

Added kubetest4j to the testing frameworks list in README_SOURCE.md with a clearer description (automatic resource lifecycle, multi-cluster support, integrated log collection). Removed a duplicate entry to keep the list clean.

^{Written for commit 9c5eca7. Summary will update on new commits.}

[cubic-dev-ai]

All reported issues were addressed across 1 file

<sub>Reply with feedback, questions, or to request a fix.

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