Update action-junit-report to version 6

[mareknovotny]

saw this in logs

2026-01-11T03:57:09.0830883Z ℹ️ Posting with conclusion 'success' to https://github.com/kiegroup/kogito-runtimes/pull/140 (sha: 1d868acc56ad6efdd2546c7b754f3b9d020c7822)
2026-01-11T03:57:09.0831981Z ##[endgroup]
2026-01-11T03:57:09.0832834Z ##[group]🚀 Publish results
2026-01-11T03:57:09.0833981Z ℹ️ - JUnit Test Report - 91 tests run, 91 passed, 0 skipped, 0 failed.
2026-01-11T03:57:09.0883234Z ⚠️ No annotations found for JUnit Test Report. If you want to include passed results in this table please configure 'include_passed' as 'true'

so trying to solve that by upgrading to better logged/handled errors mikepenz/action-junit-report#1266 in junit GHA