Make DOCA 3.2 LTS the default DOCA baseline

[viniciusferrao]

Summary

• make latest-3.2-LTS the default DOCA LTS baseline in repo generation, examples, and sample answerfiles
• keep latest-2.9-LTS on the legacy repo/kernel-support path for explicit older-stream coverage
• treat latest-3.2-LTS like the modern major-version DOCA layout so EL8/EL9/EL10 use the rhel8/rhel9/rhel10 repo targets and DKMS path
• refresh xCAT/answerfile fixtures so the repo baseline is consistently 3.2 unless a legacy-path test is intended

Validation

• cmake --build /home/ferrao/opencattus/build-host --target OpenCATTUS-tests -j8
• ctest --test-dir /home/ferrao/opencattus/build-host --output-on-failure
• git diff --check
• bash -n test/sample/confluent-deploy-full.sh

Notes

• this keeps explicit legacy coverage for latest-2.9-LTS while moving the project baseline to the current LTS stream
• this narrows later runtime validation to the DOCA 3.2 lane first, which is the intended direction for follow-up lab work

Refs #13
Refs #12