[Bug]: Race condition in report code

<!-- Please use this template while reporting a bug and provide as much info as possible. Not doing so may result in your bug not being addressed in a timely manner. Thanks! If the matter is security sensitive, please disclose it privately to a security contact: https://github.com/kudobuilder/kuttl/blob/master/SECURITY_CONTACTS --> **What happened**: On a doc-only update PR the e2e test [failed](https://github.com/kudobuilder/kuttl/actions/runs/12118493894/job/33785270307?pr=583) like this, showing unsorted `testcase` content: ``` --- kuttl-report-test.json.golden 2024-12-02 12:19:29.551188641 +0000 +++ kuttl-report-test.json.normalized 2024-12-02 12:21:34.080524663 +0000 @@ -13,12 +13,6 @@ "testcase": [ { "classname": "suite1", - "name": "test0", - "timestamp": "2000-01-01T00:00:00.00000000+00:00", - "time": "1.0" - }, - { - "classname": "suite1", "name": "test1", "timestamp": "2000-01-01T00:00:00.00000000+00:00", "time": "1.0", @@ -29,6 +23,12 @@ }, { "classname": "suite1", + "name": "test0", + "timestamp": "2000-01-01T00:00:00.00000000+00:00", + "time": "1.0" + }, + { + "classname": "suite1", "name": "test2", "timestamp": "2000-01-01T00:00:00.00000000+00:00", "time": "1.0", ``` **What you expected to happen**: The test cases in a suite should be sorted. **How to reproduce it (as minimally and precisely as possible)**: Run e2e test and get (un)lucky. **Anything else we need to know?**: The reporter code should lock the parent `Testsuite` and sort the `Testcases` slice after each modification. **Environment**: - Kubernetes version (use `kubectl version`): - KUTTL version (use `kubectl kuttl version`): - Cloud provider or hardware configuration: - OS (e.g. from /etc/os-release): - Kernel (e.g. `uname -a`): - Install tools: - Others: